Syed Mustafa Siraj was born in a village named Khoshbaspur in the district of Murshidabad in 1930. He grew up in a home with a strong literary background surrounded by books and familiarity with several languages including Arabic, Persian and Sanskrit. His mother who wrote poetry was influential. In his youth he was involved with Leftist politics and was active with the folk drama group "Aalkaap" for six years (1950–56) where he played the flute and was a teacher of folk dance and drama. He traveled rural West Bengal including the districts of Murshidabad, Malda, Burdwan, Birbhum and also performed in Kolkata. In those days, he used to perform whole nights and sleep during the day. These experiences would influence his later writing.