Introduction: The healthy carrier is the main disseminator of pneumococcal infections through nasopharynx; an alternative for treatment is a medicinal plant. Objectives: To determine the effectivity of ten medicinal plants against Streptococcus pneumoniae. Design: In vitro experimental study. Biologic materials: Medicinal plant extracts and Streptococcus pneumoniae strains. Interventions: Ten medicinal plant extracts were put in contact in vitro with 10 different Streptococcus pneumonia strains. Main outcome measures: Medicinal plant extracts activity against Streptococcus pneumoniae strains. Results: Only almendro y Bellaco caspi showed small inhibition halos with some strains; with almendro two of 10 Pneumococcus strains were inhibited and with Bellaco caspi seven strains were inhibited and three were resistant. These results had no relation either with Pneumococcus serotype or with an...