He was a student at the high schools of Beja, Évora and Coimbra, where he attended the Agricultural School, before moving on to the Faculdade de Direito and the Faculdade de Letras in Lisbon, where he graduated in Historical and Philosophical Sciences (1935).

Subsequently, a grant from the Institute of High Culture allowed him to attend the Institute of Art and Archaeology at the University of Paris in the academic years between 1937 and 1939, under the guidance of professors and historians Élie Lambert and Henri Focillon. This enabled him to specialise in the archaeology of medieval architecture, and he used the opportunity to visit other European countries, studying medieval monuments there and visiting museums.

Returning to Portugal in 1940, he was involved in the conception of the Lisbon City Museum (1940-1943).

He began his academic career as professor of Aesthetics and History of Art at the Faculdade de Letras of the University of Lisbon (1946), which he held until his death (1966). 

In the subjects he lectured, he was probably the first art history teacher at the Faculdade de Letras to use slide projections in his classes. In fact, Mário Tavares Chicó was one of the first Portuguese art historians to use photographic images as a support tool for his research, valuing the work of the photographers he worked with, such as Mário Novais.

At the beginning of 1951, at the proposal of Mário Tavares Chicó, a brigade was created to study the monuments of the State of India, called the Mission to Study the Monuments of Goa, Daman and Diu, which, for two months that year, mapped and studied the main historical monuments built in those territories, producing extensive photographic documentation.

Mário Tavares Chicó was also a member of the National Academy of Fine Arts and organised numerous exhibitions in Portugal and abroad, especially in Brazil.

He was a member of the committee overseeing the new building at of the Faculdade de Letras of the University of Lisbon.