During recent cropping seasons, leaf miners (family Agromyzidae), which usually are abundant and defoliate plants, have become major pests of tomato (Solanum lycopersicum L.) crops in northern Sinaloa, Mexico. The aim of this study was to identify the species of leaf miner in tomato crops and the parasitoids that naturally regulate them in northern Sinaloa. Tomato crops were sampled every 2 weeks from October 2013 to February 2014. Leaf blades with evidence of leaf miner were collected and confined in disposable plastic cups until adult leaf miners or parasitoids emerged. The species of leaf miner was Liriomyza sativae Blanchard. Associated parasitoid species were Neochrysocharis sp., Closterocerus sp. Ashmead, Opius sp. Muesebeck, and a species not yet identified in the family Figitidae. Parasitism of leaf miners per sample date ranged from 10 to 80%, and total parasitism per sample area was 21 to 28%.