Oshinowo studied at The Ahmadu Bello University, Zaria. He joined the teaching staff of King’s College in 1972. By 1973, Yusuf Grillo had persuaded him to teach part-time at the Yaba College of Technology. He was assigned to teach the pictorial composition class on Tuesdays. He would teach that class on Tuesdays for the next 34 year. He joined the art department as a full-time lecturer in 1974.
His mission was to teach his student to be artists. This went beyond just painting or sculpting. It encompassed their ideas about their profession and their role in society. He wanted his student to learn from an early stage to respect their calling. This, for him, was the first step to being an excellent artist. He would share his work habits as well. He was a prolific painter, capturing the everyday lives of the people around him – traders, cobblers, mechanics, people leading everyday lives – with warmth and compassion. He also explored the evolving urban landscapes of cities like of Lagos and Abeokuta.
His style, his discipline and his strong ideas about conduct would remain a part of the DNA of the Yaba school.