Mr. Nyaoga was the Chair of ICJ Kenya from 1999-2003.  During his time at ICJ Kenya, he was also the Chairman of the Executive Committee for the Access to Justice and Human Rights in Africa Initiative, a joint project of ICJ Kenya and the Sweden International Programme.

Some of his other past work includes being a member of the Commission of Inquiry into the assassination of Robert Ouko, and a member of the Goldenberg Commission that looked into a massive financial scandal.

He is an advocate of the High Court of Kenya, and is currently the Managing Partner at Mohammed Muigai Advocates. He is highly involved in corporate initiatives, being the Director of the Capital Markets Authority, a Director of Telkom Kenya Ltd, a trainer at the Centre for Corporate Governance, and a consultant for SUNNY Kenya, among other things.