Martino played mostly for Newell's Old Boys in his native Rosario. He holds the record of appearances with the team playing a total of 505 matches in all official competitions. He was also selected in a fan's poll as Newell's best player throughout the club's history.
Martino was chosen to replace Tito Vilanova as manager of FC Barcelona at the start of the 2013–14 season, but announced his resignation on 17 May 2014, though his side finished runner-up in both the Copa del Rey and La Liga that season. In 2015, he led Argentina to the Copa América Final, only to be defeated by hosts Chile on penalties. His team also finished as runners-up in the Copa América Centenario, again losing to the defending champion Chile on penalties. On 5 July 2016, Martino resigned from the Argentine national team.
Martino was assigned as head coach of the Paraguayan national football team in February 2007, replacing Uruguayan Anibal "Maño" Ruiz. His knowledge and success while coaching Paraguayan clubs were the parameters that positioned him as the best option for the job (other candidates were Nery Pumpido and Miguel Ángel Russo). Previously, Martino had won the Paraguayan league four times from 2002 till 2006.
In 2008, Martino was linked for vacant managerial position of Iran Pro League side Steel Azin but the deal was cancelled due to personal reasons. On 5 July 2010, Martino announced that he would be stepping down as Paraguay coach on their return from the 2010 FIFA World Cup in which he led Paraguay to quarter-finals. Martino confirmed that with his four-year contract expiring, he would not be extending his spell in charge of the national side. However, on 10 July 2010, Martino agreed to stay on as Paraguay coach until after the 2011 Copa America, in which Paraguay were runners-up after losing to Uruguay in the final.
After Hernán Darío Gómez's departure from the Colombian national team, Martino received a proposition to coach the team but turned it down, opting instead to coach Newell's Old Boys, one of his former clubs as a player and a club which at the time was dangerously close to relegation to the Primera B Nacional, the second tier of Argentine football. However, a series of impressive results under Martino secured top-flight status for Newell's and Martino's reputation as a coach increased quite significantly.
Following his excellent first season at Newell's, Martino won the 2013 Torneo Final, the second and final stage of the Argentine Primera División season and reached the semi-finals of the 2013 Copa Libertadores. As a result, Martino won further plaudits as a coach, having transformed Newell's from a team facing relegation on his arrival to a title-winning side, in addition to the arguably more impressive feat of reaching the 2013 Copa Libertadores semi-final, the pinnacle club competition organized by CONMEBOL. It was this startling turnaround that further increased Martino's stock as a coach, and his achievements at Newell's soon caught the attention of various clubs in Europe, including FC Barcelona.
On 22 July 2013, Martino was confirmed as manager of Spanish club Barcelona to replace Tito Vilanova who resigned three days earlier. He signed a two-year deal at Barcelona. His first competitive game in charge of Barça was on 18 August 2013 against Levante, a game which Barcelona won 7–0 on the opening weekend of the 2013–14 La Liga season. On 26 October 2013, Martino won 2–1 against rivals Real Madrid at the Camp Nou, winning his first Clásico as a Barcelona manager. Three days later, Barcelona went on to win 0–3 at Celta de Vigo and Martino became the first coach in Barcelona history to not lose a game in their first 16 matches. On 26 November, Martino's unbeaten start as Barcelona coach came to an end after his 21st game in charge, as Barcelona lost 2–1 away at Ajax in the 2013–14 UEFA Champions League. After conceding the 2013–14 La Liga title on the last day of the season to Atlético Madrid, Martino announced he was to leave his role after just one year in charge during which he did not manage to win any major trophy except the Spanish Super Cup.
On 12 August 2014, Martino was introduced as the new manager for the Argentine national team, succeeding Alejandro Sabella who took the side into the final against Germany at the World Cup in Brazil. In the 2015 Copa América, he reached the final, in which Argentina were runners-up after losing to hosts Chile on penalties. They also finished as runners-up in the Copa América Centenario Final on 26 June 2016 against Chile, again losing on penalties. On 5 July 2016, Martino resigned.
After departing from Argentina, Martino was announced as Major League Soccer expansion team Atlanta United's inaugural season manager on September 27, 2016.
Gerardo Martino prefers to play a very high pressing and an attacking style of football. At Barcelona, Martino continued the club's preferred style of play tiki-taka along with his own tactics. All of Martino's teams have the same distinguishable traits: they play attack-minded football, they are creative and the style is based on quick passing. In addition, Martino's teams also pressure high up the pitch, play out from the back and depend on their youth systems.As of 29 July 2017.
Gerardo Martino is of Italian descent. His grandparents are from Ripacandida, Basilicata. Martino is married to fellow Argentine María Angélica.Newell's Old Boys
Argentine Primera División (3): 1987–88, 1990–91, 1992 (Clausura)
Paraguayan Primera Division: 2002, 2003, 2006
Paraguayan Primera Division: 2004
Newell's Old Boys
Argentine Primera Division: 2013 Final
Copa América Runner-up: 2011
Supercopa de España: 2013
Copa del Rey Runner-up: 2014
Copa América Runner-up: 2015, 2016
South American Coach of the Year (1): 2007