This research was directed to analyze the factors that affect the English language teaching-learning process in Ecuadorian public high schools. The sample analyzed consisted of fifteen students and fifteen teachers, who were surveyed and interviewed to determine their skills and competences and a similar number of classrooms observed to find out their physical conditions. The research was carried out at daytime and evening in four public high schools and one “fiscomisional” in rural and urban areas of Quito. To collect data, the techniques used were surveys and note taking; additionally, the applied instruments were observation forms, interviews and questionnaires. The quantitative analysis, description and interpretation of results were based on the information gotten from: Teacher’s and Student’s Questionnaires and Interviews, Observation Sheets and researcher’s field observations. The most relevant factors found were students’ basic level of English knowledge, use of few teaching resources and a high percentage of Spanish use in class, the overcrowded classrooms and inappropriate physical conditions, which affected negatively. Contrasting, the frequent lessons design monitoring and teachers’ commitment and experience influenced positively the English language teaching-learning process.