In addition, Onosode was the inaugural President of the Chartered Institute of Stockbrokers, past Pro-Chancellor and Chairman of the Governing Council of the University of Uyo and past and inaugural President & Chairman of Council of the Association of Pension Funds of Nigeria.
Though, he was a part of a profligate democratic experiment which was the Nigerian Second Republic,[6] Gamaliel Onosode tried to bring a disciplined approach to public finance.
The report identified five major defects in planning which it believed had become evident by the end of 1983: In 1995, he became the Chairman of the Niger Delta Environmental Survey, a non-governmental organisation that conducted scientific studies on environmental and social impact assessment of oil exploration in the Niger delta.
The survey reports which apportioned responsibilities and blame for much of the environmental degradation in the region on oil operators, the federal government and communities has not been made public.
Gamaliel & Susan Onosode Foundation[12] His philanthropy was one to be reckoned with in his life time, a legacy he transferred into corporate existence with the founding of GAMSU.
In recent times, the organisation made a donation to the Lagos Business School[13] for the building of a research facility in memory of Gamaliel Onosode.
A partnership with General Electric Healthcare Institute allowed GAMSU train 45 nurses in Lagos[14] as part of a drive to improve the maternal mortality rate in Nigeria.
The organisation also pursues school rehabilitation projects and provide facilities[15] to help create a better teaching and learning experience.