BACKGROUND Poisoning caused by "black widow" spider bite, is not commonly observed during childhood, it is not exempt from complications, and must be treated in time or the patient can die. In Mexico we do not have accurate data on the exact number of accidents due to this condition. OBJECTIVE Identify the signs and characteristic symptoms of children treated at the Children's Hospital from the state of Sonora with the aim of starting early treatment. METHODS We reviewed 43 clinical records of hospitalized patients admitted for "black widow " spider bite between 1978 - 2004. Demographic variables were: age, gender, place of origin, place where accident took place, treatment given prior to hospital admittance, degree of envenomation measured by signs and symptoms, treatment and clinical evolution. RESULTS 69.7% of cases were male, we did not find differences in the number of patients between infant, pre-school, elementary school children and teenagers. During summer and afternoon hours we registered 44% and 37% cases respectively; 74% patients were poisoned by the spider at home; the anatomical areas most affected were: arms, hands and thorax. Signs and symptoms in infants were: irritability, constanty cry, sialorrea, agitation erythema on wounded areas and seizures. Among elementary school children and teenagers signs included pain in wounded area, abdominal and thoracic, muscle spasms, fine tremor and residual signs. Patients who received fabotherapic treatment had better evolution and less time of hospitalization. No deaths were reported. CONCLUSIONS The different signs and symptoms between infants, preschool, elementary school children and teenagers allowed us to clearly identify evenommation and differentiate it form confounding diseases. In our study, specific fabotherapy constituted the best treatment choice.