Lanari started his career in 1980 with 2nd division outfit Sportivo Italiano, where he stayed until 1986, making over 200 appearances for the club. Subsequently, he joined Rosario Central. Lanari helped Central win the Primera Division in the 1986-87 season.
In 1991. he moved to Mexico to play for Tigres, but returned in 1995 for a brief spell with Racing Club before moving to Argentinos Juniors. Argentinos were relegated in 1996 and Lanari played for them in the 2nd division for a season before he was signed as a reserve goalkeeper for Boca Juniors, where he retired in 1998 at the age of 38.