Rokitamycin (RKM) dry syrup was administered to a group of pediatric patients. The results obtained are summarized as follows. 1. Of the recent isolates of Streptococcus pyogenes, fewer strains were highly resistant to RKM than to josamycin (JM), midecamycin (MDM), erythromycin and lincomycin. Also, macrolides (MLs)-resistant strains proved to be susceptible to RKM. 2. Recent isolates of Staphylococcus aureus, Streptococcus agalactiae, group G Streptococci, S. pyogenes, Streptococcus pneumoniae and Haemophilus influenzae were more susceptible to RKM than to midecamycin acetate and JM. Oral administrations of 10-15 mg/kg of the drug were followed by its peak concentrations of 0.07-0.77 micrograms/ml in the blood at 30 minutes in many patients, and by an undetectable level at 6 hours also in many of them. T1/2 values were 1.2-2.6 hours, and first 6-hour urinary excretion rates were 1.26-1.74%. 3. Fifty-two patients with acute upper and lower respiratory tract infections, Campylobacter enteritis, etc. were treated with RKM at about 20-40 mg/kg daily for 4-14 days, with an overall efficacy rate of 88.5%. 4. An eradication rate of 81.4% was achieved for 43 strains of 7 species isolated from the patients. 5. No abnormal laboratory test values were observed after treatment with drug 4 approximately 14 days. A side effect, stomach discomfort, was observed in 1 patient.