In 1992 he won the world title at Aprilia in the 125cc class of the MotoGP World Championship.
After Alessandro Gramigni had made a series of good results in amateur races attention to himself, he began in the 1990 season of his career in the 125cc class of the Motorcycle World Championship. He started on an Aprilia and managed in his first season with second place in Sweden and third place in the Czech Republic retract two podiums. In the overall standings Gramigni reached the eighth place with 84 points. The following season he started continues in the 125cc class for Aprilia Team Italia. At the race in Brno Alessandro Gramigni celebrated his first Grand Prix victory in the overall standings, he reached this year with 90 points in seventh place. 1992 Gramigni was somewhat surprising world champion in the eighth liter class. After the World Cup the last two years, compatriot Loris Capirossi, was changed to the 250cc class, Alessandro Gramigni could win with two wins and seven podium finishes in twelve races the title. In the overall classification he had at the end of the season with 134 points, 16 points more than his closest rival Fausto Gresini.
For the 1993 season then rose to Gramigni in the 250 cc class, where he first started to Gilera and Aprilia later on. With two meager points, he did not make it past the 30th place in the overall standings. In 1994 and 1995 launched the Italians in the 250cc World Championship, but to be successful without. He reached in these two years only 23 overall. Thereafter, the Florentine was no more space than a regular driver in the championship.
For the 1997 season Gramigni was committed by Aprilia test rider for the 500cc class and denied the Grand Prix of Malaysia his last Grand Prix. In 1998, Alessandro Gramigni then withdrew from the World Motorcycle Championship, to compete in the Italian Superbike Championship. In the 2004 season he won 391 Racing this on a Yamaha team.
From 1998 to 2000 Alessandro Gramigni first started on Ducati and Yamaha permanently later on in the Superbike World Championship. His best World Cup placing it he scored 1998 rank 14 Then the Italians launched until 2005 sporadically in this series.