While barbiturates are still the hypnotic-sedative drugs most frequently used in suicide attempts, newer agents are of increasing popularity, leading at times to diagnostic and therapeutic puzzlement. Our recent experience with 5 patients intoxicated with ethchlorvynol (Placidyl) prompted an evaluation of its toxicity and hemodializability. Three patients, ingesting 100, 169 and 157 mg of ethchlorvynol kg respectively, were seriously ill, hypotension and respiratory depression being prominent in the latter. Using the Twin-Coil dialyzer, ethchlorvynol dialysance in vivo is as high as 111 ml/min at 510 ml/min. blood flow rate. Two patients underwent hemodialysis, with dialysate recovery of approximately 2500 mg. in 14 hours, and 3500 mg. in 18 hours, respectively. It is suggested that hemodialysis, in conjunction with optimal conservative attention, may be usefully employed in instances of serious intoxication with ethchlorvynol, and that comatose patients with suspected ethchlorvynol ingestion of 100 mg/kg. or more, and/or serum concentration exceeding 4.5 mg/100 ml 12 hours after ingestion, be considered to be candidates for hemodialysis.