In a popular referendum on 28 February 2005 the people of Burundi overwhelmingly approved a post-transitional constitution.
Senate members were indirectly elected on 29 July 2005 by an electoral college of commune and provincial councils.
Philippe Rivuzumwami was elected Tutsi Senator for Kirundo Province on the platform if the National Council for the Defense of Democracy – Forces for the Defense of Democracy (CNDD-FDD).
Pascal Musoro was elected Hutu Senator for Kirundo and Charles Masabo was coopted as Twa Senator for Kirundo.
In June–July 2007 Philippe Rivuzumwami was a member of a Senate commission to report on the situation around the border between Burundi and Rwanda, reporting their findings to the senate.