Visaka Dharmadasa is the founder and Chair of the Association of War Affected Women and Parents of Servicemen Missing in Action. This organisation educates soldiers and community leaders about international standards of conduct in war, including treatment of prisoners of war. She is also a member of Inclusive Security Women Waging Peace, the Global Network of Women Peacebuilders and is a Director of the National Peace Council of Sri Lanka. She has previously conducted research for the Human Rights Commission of Sri Lanka on ceasefire violations. In 2006 she was presented with the Humanitarian Award by InterAction.

Visaka Dharmadasa is a member of Women Mediators across the Commonwealth (WMC), a network hosted by Conciliation Resources which connects women with a broad range of mediation knowledge and experience.