Cases of nontuberculous mycobacterial lymphadenitis were analyzed in a prospective study spanning 32 years, from 1958 to 1990. The results are based on personal observations and long-term follow-up. There were 105 cases, all of which occurred in children aged 9 1/2 months to 12 years (median age, 2.92 years). The patients were predominantly female, and the cases occurred more often in the winter and spring. The cervical or facial nodes were involved in 96 cases. An abrupt change in the predominant etiologic agent (from Mycobacterium scrofulaceum to Mycobacterium avium complex) was noted in the 1970s. Positive tuberculin skin tests were the rule, and reactivity was long lasting. Complications included a prolonged initial phase of infection (n = 6) and recurrences 3 1/2 months to 7 years later (n = 5). Resection during the early stage of infection produced the most satisfactory healing.