Mary received her first degree in adult education from the University of Dar es Salaam. In 1983 she went to New Zealand for further studies where she obtained her Masters degree in social education. She also received a certificate of gender development education from London, UK. From the year 1988 to 1993, she worked with the Embassy of Canada as a gender expert before moving on to the Dutch Embassy for similar responsibilities until 1997.
Mary was one of the co-founders of Tanzania Gender Network Programme (TGNP) in 1993. She was eventually appointed the second Executive Director of the Network in 1997. Mary Rusimbi is a renowned activist, researcher and consultant for gender and development issues.