Voina began his coaching career with Steaua, he led them to nine national championships and one EHF Champions League final.

[2] In the 2009–2010 season, he managed to qualify his team CS Oltchim Râmnicu Vâlcea in the Women's EHF Champions League Final for the first time in the history of the club.

Voina coached the Romanian national team to a third-place finish in the 2010 European Women's Handball Championship.

At the end of the season, Radu Voina decided to take a break so he didn't renew his expired contract with CS Oltchim Râmnicu Vâlcea, but he remained the coach of Romania.

In March 2011, he replaced Anja Andersen on the bench of the Romanian team CS Oltchim Râmnicu Vâlcea.