The aim was to determine the relationship between family functioning and suicidal ideation in high school students of state educational institutions of Villa El Salvador-Peru. The study had a quantitative approach, non-experimental design and correlational type. The sample consisted of 225 female students and 213 male students, aged 12 to 17 years. The instruments used were the Family Apgar Scale and the Suicidal Ideation Scale (SSI). The results showed that the level of mild family dysfunction predominated with a percentage of 34.0%, while the medium level predominated in suicidal ideation with 40.6%; in addition, a significant relationship was found between family functioning and suicidal ideation (p=.000), and a statistically significant relationship between the levels of family functioning and each of the dimensions of suicidal ideation with a Cramer’s V association of median size (<.20). It was concluded that the higher the family functioning, the lower the suicidal ideation.