We have observed 20 patient, who were intoxicated with Rodenticide RH-787 for .suicidlal .atempts between March '76 to August '76, and obtained several following results. 1. Among 30 intoxiciated patients, male was 5 and female was 25. The age distribution was between 15 to 39 years uId and most of them were between 15 to 39 years old. The ingeested dose of RH-787 Was between 250~1,500 mg and most of thern were below 500mg. 2. The most striking clinical symptoms were sore throat, general ache, dysesthesia, eplgastrie dliscomfort and general weakness. Physical examinatian revealed epigastric pain, pharyngits, skin changes and bladder distersion due to disturbed micturition. 3. Abnormal laboratary findings were those of hyperglycemia, glycosuria and positive acetone test in blood and urine in 1:1 patients, and the mean blood sugar value of the patients was 461.75 mg%. The other laboratory tests such as CBC blood chemistry, serum electrolytes and electrocardiogram showed no specific abnormality. Observable complicaticins were diabetes rnellitus, pharyngitis, peripheraI neuritis and voiding disturbance due to neurogenic bladder and most of above complicationss were observed at the same times. We could not observe satatistically significant, correlation between the dose of RH--787 ingested and the occurrence of diabetes mellitus. 6. There was staistically significant correlction between the time of first aid and the occurrence of diiabetes mielltus and in the cases who were treated within 3 hours after. Ingestion with gastric large no accurence of diabetes mellitus was observed. 7. Among 14 complicated diabetes mellitus,5 were controlled with NPH 24~60 umits per day, 8. Nicotinamide which had been recommended as a specific antidote to RH-787 by the manifacturer showed no effect in the treatrment of petients who were complicated with diabetes mellitus peripheral neurits and neurogenic bladder. 9. 9 patients(20%) were dead during hosiptalizatiorn and the causes of deah were diabetic ketoacidoxis in3, hypoglycemic coma in 2 and unknown in 4, 10. The exact mechanism of the toxic effect of RH-787 to human body are not clearified yet, so more intensive studies should be necessary.