Objective To determine the urinary citrate (UC) level in stone formers (SF) versus controls. Study design Case control study. Place & Duration of study Department of Pediatric Nephrology, National Institute of Child Health (NICH), Karachi from January- July 2008. Methodology Eighty six children of 1-13 years, 43 in each group, stone former (SF) and controls were studied. In both groups, 24-hours UC was measured by citrate lyase method. Hypocitraturia was defined as 24- hours UC-level < 5mg/kg for children under 9 years and <7mg/kg for 9 years and above. Data including age, sex, weight, 24-hours urine volume (UV) and UClevel were analyzed using descriptive statistics on SPSS version 15. Results Of the 86 children, 59 (68.6%) were males and 27 (31.4%) females. Overall mean age was 5.65 + 3.05 years, while that of SF and controls was 5.61+ 3.1 and 5.70 + 3.04 years respectively. Mean 24-hours UV and UC-level in total of 86 samples was 385.10+130 ml and 88.10 + 62.11mg respectively. Mean + SD 24-hours UC-level (mg) in SF and controls was 69.4 + 53.55 (95%CI 53.39-85.41) and 106.8 + 65 (95%CI 87.37-126.23) respectively. Overall hypocitraturia was found in 42(48.8%) children. Frequency of hypocitraturia was high in SF (n 30, 69.8%) compared to controls (n 12, 27.9%) with a significant difference between the two groups (p<0.001). Conclusions Overall hypocitraturia was found in 48.8% of cases. Though hypocitraturia was prevalent in both groups, but was significantly high (69.8%) in SF compared to controls (27.9%). Hypocitraturia may be an important metabolic risk factor and urinary citrate level should be included in the metabolic evaluation in all stone formers.