mahama went back to nalerigu as a medical doctor in september 1973 and four years later, he left ghana to become an obstetrics and gynecology physician in chicago, illinois. during this period, he was also a clinical instructor at northwestern university. in 1990, mahama was appointed a lecturer at the university of ghana medical school and consultant at accra's korle bu teaching hospital. he was elected a fellow of the west african college of surgeons in 1994.