Lastimosa was one of the original members of the Purefoods TJ Hotdogs franchise upon its entry into the league in 1988 as one of the illustrious quartet which included PBA 4-time MVP Alvin Patrimonio, many-time "Mythical Team" and All-Defensive Team Member Jerry Codiñera and perennial All-Defensive Team member, Glenn Capacio.
In 1988, Jojo Lastimosa came into the league fresh from an amateur stint. He won Rookie of the Year honors and was named to the Mythical Second Team in the same year.
However, Lastimosa did not last long at Purefoods as he was traded to Alaska Milk in 1991 in a trade with Cabahug. At Alaska, his career further blossomed as he became an integral part of the Triangle offense. In his first season with Alaska, Lastimosa played the best season of his career, leading the league in statistical points before narrowly losing the MVP award to former teammate Alvin Patrimonio. With Alvarez recovering from injury, Lastimosa carried Alaska, which had its finest season in the league until that point, winning the first championship in franchise history in the Third Conference that year. He skippered the Milkmen to the 1996 Grand Slam together with eventual 1996 MVP Johnny Abarrientos, Bong Hawkins and Jeffrey Cariaso, only the fourth Grand Slam in the league's history. During his stay with Alaska, he became a permanent fixture in the "Mythical Team" selection.
In 1998, he again led the Alaska team to the championship of both the All-Filipino and Commissioner's Cups together with Abarrientos, Hawkins and Kenneth Duremdes. The Grand Slam was then again beckoning but his inclusion to the 1998 Centennial Team (together with Abarrientos and Duremdes) that played in the 1998 William Jones Cup (Champions) and the Bangkok Asian Games (Bronze Medal) prevented the team from repeating their 1996 feat. He was turning 35 when as a member of the RP team to the 1998 Asian Games,
After a long association with the Alaska team, Lastimosa was traded to the Pop Cola Panthers where he formed a deadly triumvirate with Nelson Asaytono and Noli Locsin. However, they were not able to turn the tide for the then struggling Pop Cola team.
In 2002, Lastimosa found his way back to the Alaska Aces franchise where he ended his career in 2003.
During halftime of their 2003 season opening game, Alaska retired Lastimosa's #6 jersey. During the off season, Lastimosa announced his retirement after playing 15 seasons in the league.
He finished his career with over 11,000 points. One of the high points in his career was his game against Kazakhstan in the battle for third place in the 1998 Bangkok Asian Games where the Philippines captured the bronze medal.