Lipids from Helicobacter pylori were extracted, isolated by conventional DEAE-Sephadex and silica gel column chromatography, and then purified by preparative thin-layer chromatography. Simple and phospholipids were analyzed by HPTLC and quantitatively determined by densitometry scanning. The fatty acid compositions of simple lipids were estimated by gas-liquid chromatography. The simple lipid composition of H. pylori consisted of wax ester (2.5%), triglycerides (4.9%), free fatty acids (30.0%), cholesterol (6.9%), diacylglycerol (29.1%), and monoacylglycerol (2.6%). The neutral phospholipid composition consisted of phosphatidyl ethanolamine (79.1%), lysophosphatidyl ethanolamine (16%), and phosphatidyl choline (1.9%). That of acidic phospholipids consisted of phosphatidic acid (52.7%) and phosphatidyl serine (47.3%). The major fatty acids of crude lipid, wax, free fatty acids, triglycerides, diacylglycerides, and monoacyl glycerides were C19:1 (cyclo), C18:2, C16:0, C19:1 (cyclo), C22h:0, and C18:0, respectively. These results are new findings and suggest significant characteristics from the metabolic, physiologic, and chemotaxonomic point of view.