The agency was awarded the account following a five-way pitch.
XL was launched in Poland in 2000 and is sold in over 70 countries worldwide. It sells more than 170million cans per year and has a strong audience in the UK's clubbing and promotion scene. It is a challenger to brands including Red Bull, Monster, Shark and Rockstar.
Voice Communications is the first PR agency support the brand has hired in the UK.
It will handle media relations, exhibition support and sponsorship exploitation as part of the brief. It will also include a consumer campaign launched later this year working with social networking website partners.
The agency will target drinks trade, clubbing, music and men's and women's consumer titles.
Voice MD Nichola Cain will report into XL general manager Kobi Ludwin.