Giani’s father, Dario, was a rower who had taken part in the 1964 Summer Olympics for Italy. After having trained with the father, now a rowing coach, Andrea tried for brief period as a football player, in 1985 the 14-year-old Giani began his career as a volleyball player in the local team of Sabaudia, in the Southern Latium, where he lived. Soon news about his qualities spread and attracted attention from the two main volleyball club of Italy of the period: Panini Modena and Santal/Maxicono Parma. Giani was chosen to play for the latter, initially with the junior team under Gian Paolo Montali as coach. Giani’s first final for scudetto in the Parma major team was in 1987. Parma was defeated, as well as in the following seasons. Giani won in 1990 his first scudetto, it was to be followed by four more. In the meantime, in 1988, Giani had scored against Finland his first cap for the Italy, his career with the Azzurri colours ended in 2005 after a total of 474 caps, becoming one of the most renowned players in Italy and in the world for his excellent technical and jumping capabilities. With Italy Giani won three World Championship titles in a row and four European Championship and many others. He won three medals at the Olympic Games but his team never won the gold medal, even though Italy was generally considered the top favourites. He won silver medals at the 1996 Olympic Games and 2004 Olympic Games, and a bronze medal at the 2000 Olympic Games and make Golden time with team other members. During his career Giani became renowned for his polyvalence, starting as a middle blocker, he turned into a power attacker and passer. Giani before Modena, played in Parma 1985-1996 and winner three Italian ChampionshipSerie A and Club World Championship. After having quit the national team, Giani played for Cimone Modena until 2008 and winner two CEV Champions League. He taking the reins of the team as manager starting from season 2007–2008. His nickname is Giangio and at the season winner CEV Challenge Cup 2008. Giani at 2009-2010 year won Championship Serie A2 with M. Roma Volley. Giani became the manager of the Slovenia men's national volleyball team in May 2015. Few months later he led Slovenia to victory in the European Volleyball League, which secured them a spot at the 2016 FIVB Volleyball World League. In October Slovenia unexpectedly won their first medal on a major volleyball tournament, after reaching the Final of the 2015 Men's European Volleyball Championship where they were defeated by France. In 2017, Giani replaced Vital Heynen as head coach of the Germany men's national volleyball team.