The Pinamou traditional procession is a ritual performed on female adolescents over the transition to adulthood. They were exiled to Posune (small hut) to undergo the Pinamou ritual during menstruation. During this procession, there are various activities related to personal hygiene that can adversely affect the health of young girls. The present study elaborated and traced the beliefs adopted by the Nuaulu female adolescents displayed in their local customs using ethnographic designs. Sources of information were traced through the snowballing technique. The findings reveal that the belief adhered to by girls related to personal hygiene is a ban on bathing during seclusion in Posune. Their bodies are only covered with charcoal. Replace traditional pads made of cloth that are used repeatedly only 2-3 times a day. Defecation is done in the middle of the forest and should not be seen by the opposite sex. Violation of the provisions of the Pinamou traditional procession is believed to trigger disasters for individuals, families, and village communities.This finding has implications for the need for a cultural communication strategy to wisely shift traditional activities that negatively impact the health of young girls through customary stakeholders, community leaders, and the local government.