Lumbar curvatures in 149 normal adults from the general population were studied. There were 76 men and 73 women with an average age of 50 years. The mean values of lumbar lordotic angle (LLA), lumbosacral angle (LSA) and sacral inclination angle (SIA) were 33.2 +/- 12.1 degrees, 11.4 +/- 4.7 degrees and 26.4 +/- 10 degrees, respectively. A high correlation was noted between LLA and SIA (r = 0.883, p = 0.0001). LLA is an ideal parameter for the evaluation of lumbar lordosis. The normal value of LLA can be defined as 20-45 degrees with a range of 1 SD. No significant differences were noted in these three angles between males and females in any age group (LLA, p = 0.647; LSA, p = 0.80; SLA, p = 0.189). Also, X-ray findings indicated there were no significant differences between these three angles in spondylotic spines and those spines with a normal appearance from X-ray finding. The average LLA increased with age. Significant lumbar lordotic angle differences were noted between those patients less than 35 years of age and those greater than 60 years, as well as in the 35-60 age group and the greater than 60 age group (p = 0.0056).