He began his career in 1994–95, playing in the Eccellenza with A.S. Latina, in which he scored five goals in 26 appearances. The following season, he produced 10 goals in 31 appearances in Civita Castellana in Serie D, before moving to Fano (Serie C2), where he remained until March 1998, he played 32 games with only one goal. In 1999, Selva played with another Serie C2 club, Catanzaro, making 40 appearances, scoring six goals.
Selva went back to the Eccellenza with Tivoli in 1999, which he scored 15 goals in 21 matches, while for the following season, he moved to San Marino, where he scored four goals in 26 appearances. In the 2001–02 season playing in three different teams, he collected three appearances with San Marino, then five with Maceratese in Serie D, scoring a goal, and thus finishing the season in Serie D, with Grosseto (15 appearances and two goals). He scored 22 goals in 30 games for Bellaria in the following season.
In the summer of 2003, he transferred to SPAL where, in two seasons in Serie C1 he plays 51 games scoring 22 goals. In 2005–06, he moved to Padova (Serie C1), who sold him to Sassuolo after only scoring two goals in 20 games. With Sassuolo, he played two years in Serie C1 and played an important part in the historic breakthrough with a Serie B promotion, contributing decisively with 15 goals in and became the top scorer in Group A.
In mid-2009, he left for Hellas Verona but was released after Verona were promoted to Serie B.
In July 2011, he trained with Santarcangelo.
Selva was born in Rome, Italy to an Italian father from Lazio and a Sammarinese mother, which made him eligible to represent Italy or San Marino and chose for the latter.
He made his international debut on 9 September 1997 against Turkey U-21, and scored one goal for his team in 1–4 loss.
He is hailed as the greatest player in the current San Marino national side and one of the greatest in its history. He has appeared more than 60 times for the national team and scored eight goals, making him the leading goalscorer in the history of the team. Until 2012, he was the only player to score more than one goal for San Marino.
On 28 April 2004, Selva became the first player ever to score a winning goal for San Marino when he netted the only goal in a 1–0 friendly win over Liechtenstein, which is the only win that San Marino have recorded to date, as well as one of three official matches where San Marino have kept a clean sheet.
Score and Result lists San Marino's goals first