Glycerylphosphorylcholine (GPC), glycerylphosphorylethanolamine (GPE), citrate, and lactate content of human seminal plasma was analysed by measuring the peak area of 1H nuclear magnetic resonance (NMR) spectra in samples from four groups of patients: 21 spermatogenic failure subjects; 14 obstructive azoospermic subjects (vasectomized); seven patients presenting very severe oligoasthenozoospermia (OAT) and 18 normozoospermic subjects (control). The peak areas for GPC, citrate and lactate in seminal plasma were significantly smaller for patients with azoospermia than for the control group: 16.79, 8.18 and 2.28 versus 23.38, 10.58 and 4.30, respectively (P < 0.01). The peak area ratios for citrate:lactate and GPC:lactate were significantly different (P < 0.01) between the control group and the spermatogenic failure or obstructive azoospermia groups. A significant difference was also found in GPE:GPC peak intensity ratio between spermatogenic failure and obstructive azoospermia subjects (P < 0.001). These results provide some quantitative markers which may be used for examining infertility by using 1H NMR of seminal plasma samples.