At the time, there was a growing interest in art in Lebanon, facilitated by prominent philanthropists such as Alfred Sursock, Henri Pharaon, Omar Daouk and Camille Eddé. In Beirut, Gemayel began teaching at the Académie Libanaise des Beaux Art and exhibiting his work at various events.

Enamoured with his country, Lebanon was Gemayel’s main inspiration -- its mountains, villages, folk life, city streets and diverse vistas. Its people, too, were favourite subjects; Gemayel was a prolific artist and his sensual eye painted many nudes. All these subjects fed his love of colour – the strong shades of red, green and blue he favoured are quickly recognizable and were used to perfection toward the end of his life.

Gemayel is commonly known as a "second generation" Lebanese painter -- one of the first who managed to extract himself from the imposed classicism and religious paintings still in force in Lebanon at the time. Some people compare his style to Renoir -- maybe because both were avid painters of nudes. However, by the time Gemayel visited Paris to attend the Académie Julian, Renoir was not any more the artist "du jour"; Degas teased him and Picasso mocked him. Degas famously called Renoir's style "as puffy as cotton wool".