In 1999, at the age of 19, he made his international debut as a reserve for the Romanian national team, being one of the youngest players at the 1999 Rugby World Cup. His test debut was against Morocco national team in 2000. He won his first 14 caps as a lock, and established himself as a flanker after moving to Perpignan.
He was included in Romania's squad at the 2003 Rugby World Cup. He was injured for three months in early 2005 and took part in the 2007 Rugby World Cup, where he was Romania's vice-captain. During the latter event, as Romania prepared to face the Scotland, Toniţa was deemed "perhaps (Romania's) one world-class player" in a Scotsman article. An analysis of the Romanian squad, published by The West Australian, noted that Toniţa "is a class act in the scrum", while arguing that, given Romania's poor results: "The sad thing for him is that he is playing with the wrong generation of players." He also competed at the 2011 Rugby World Cup.