Efficacy of furazolidone and nalidixic acid was compared in a randomized trial involving 72 children with acute invasive diarrhea. Thirty six children received furazolidone (7.5 mg/kg/day) and 36 children received nalidixic acid (55 mg/kg/day). Clinical characteristics of the two treatment groups were comparable on admission. Of these, 34 children in furazolidone treated group and 29 children in nalidixic acid treated group completed the full course of treatment and were analyzed finally for clinical efficacy. Clinical cure was observed in 29(85.3%) children treated with furazolidone and 29(100.0%) children treated with nalidixic acid. Nalidixic acid treated group had statistically significantly higher cure rate (p = 0.039) as compared to furazolidone treated group. However, 85% cure rate in furazolidone treated group may be potentially useful for the treatment of acute invasive diarrhea because of decreasing efficacy of nalidixic acid against shigellosis in many countries.