Ratsimamanga was awarded the Grand Cross of the Malagasy National Order, First Class Grand Cross of the Order of Merit of the Federal Republic of Germany, Grand Officer of the Legion of Honor of France, Grand Officer of the National Order of Scientific Merit of France, National Order of the Lion of Senegal, Commander of the Ordre des Palmes académiques, Commander of the Order of Merit of Congo - Brazzaville, Commander of the Ordre national du Mérite of France, and Grand Prize from the Royal Academy for Overseas Sciences. He was selected Madagascars Man of the Century' in 1999.
Ratsimamanga was a Founder Fellow of the World Academy of Sciences (FTWAS) in 1983, and the African Academy of Sciences in 1985 (FAAS). He was awarded an Honorary Doctorate from the Cheikh Anta Diop University in 1973.