Objective: To determine the level of knowledge about self-medication in pregnancy in initial level mothers in a school in San Juan de Lurigancho, Peru Material and methods: Descriptive observational cross-sectional study applied to 20 mothers. A questionnaire of 20 questions validated by experts was carried out. Results: The age of the mothers ranged from 24 to 44 years, the level of education of 50% was secondary school and the occupation of 75% was housewife. It is shown that 50% purchased medications without a prescription and that the vast majority of respondents are aware of the adverse effects of self-medication, in addition to the establishment where they easily acquire medications are pharmacies. Conclusions: We determined that there is a good level of knowledge about self-medication but it continues to be a recurring practice today due to economic, social and cultural factors.