This study aims to document the tribal community beliefs and practices around fertility behaviours of the Porja vulnerable tribal group in Andhra Pradesh, India. With the purposive sampling method, 175 mothers of reproductive age (>15–49 years) were selected based on the inclusion criteria of having experienced fertility practices and the cultural significance associated with it. The socio-demographic profiles and the fertility rates of 175 mothers have been enumerated through household survey methods and semi-structured interview schedules. The qualitative data collection involved 42 in-depth interviews and three focus group discussions (involving 6–10 women) on specific sociocultural practices around fertility behaviour patterns. Handwritten interviews and conversations were transcribed and coded into themes and categories. Views from the themes reveal that the sociocultural environment has influenced fertility behaviours. Age at marriage and conception at adolescence are the main factors affecting tribal fertility. Traditional fertility-seeking behaviour indicated sequential care from traditional birth attendants and local medicinal women (providing medicine for early conception and birth spacing). The preference for two sons’ was the theme that largely influenced fertility trends. There is a need for comprehensive healthcare intervention in the PVTG tribal areas to lessen the unhealthy reproductive practices that affect tribal survival chances, leading to higher mortality rates.