The author devised a method which permits simultaneous isolation and identification of Chlamydia using a slide chamber with 8 wells. Contaminating bacteria were eliminated by filtration with the membrane filter. The procedure allowed isolation of Chlamydia pneumoniae and Chlamydia trachomatis from 11 (10.1%) out of 109 and 10 (9.2%) out of 109 otolaryngologic clinical specimens, respectively. The use of HL cells together with Hela-229 cells had been considered essential to isolate Chlamydia from specimens in this field. The conditions for isolating Chlamydia pneumoniae were similar to those for Chlamydia trachomatis. The slide chamber procedure with membrane filter treated specimens was suitable for simultaneous isolation and culture of various species of Chlamydia and allowed easy differentiation of Chlamydia pneumoniae from Chlamydia trachomatis with identification by the indirect fluorescent-antibody technique. Routine examination of clinical specimens using this procedure should be required in the future in order to better understand chlamydial infections.