After retiring from the game in 1998, Ambrosio took up coaching, beginning with Córdoba Rugby Club in 1999 to 2000. He returned to Italy where he was head coach of
Petrarca Rugby from 2002 to 2004 and Segni from 2005 to 2007. Following his five year stint in Italy, Ambrosio returned to Argentina to take up a newly created role within the
Argentine Rugby Union High Performance programme, becoming a Regional Manager in Córdoba before taking over the direction of the federal technical sector of the youth in the region. This position lead to him becoming the
Argentine U20 head coach in 2013, taking the national age-grade side to the
2013 IRB Junior World Championship (finishing sixth) and the
2014 IRB Junior World Championship (finishing in ninth). Returning back to coaching in 2013 later saw Ambrosio appointed head coach of
Brazi in November 2014. His reign included important wins against
Canada and the
United States, while they also broke
Argentina's domination in the
South American Rugby Championship, winning that tournament in 2018. He left his post with Brazil in 2019 after failing to advance within the
2019 Rugby World Cup qualification process, and returned to high performance with
Daniel Hourcade within
Sudamérica Rugby. As part of his role, he became head coach with newly founded Colombian side
Cafeteros Pro in 2020, but his duties were delayed by a year due to the COVID-19 pandemic. After one season with the side, and losing all games in the
2021 Súper Liga Americana de Rugby season, he stood down as head coach. In 2022 and 2023, he became a technical advisor for
Chile during their run to the
2023 Rugby World Cup, and in 2024, followed Hourcade to Portugal where he became assistant coach for their
national side during the
2024 Rugby Europe Championship. In April 2024, he was appointed head coach of
Uruguay. ==Honours==