This study analyzes the way teenagers from low socio-economic levels construct their beliefs and practices on sexuality.The research is qualitative, and specifically designed with an ethnographic approach, which is centered on the participants' description of their experiences, attitudes, values, roles, traditions, and beliefs.Also analyzed was the adoption of lifestyle-forming behaviors that construct relationships and affect the teenage pregnancy rate.That the teenagers' beliefs and practices on sexuality are the result of their cultural and traditional knowledge, the prevalence of their social dynamics, and their leisure and recreation activities was also observed.