Aim:To investigate the relationship of cholelithiasis and urolithiasis withMethylenetetrehydrofolate Reductase(MTHFR) polymorphism(s) in patients with poor obstetric history to search whether they are risk factors for adverse pregnancy outcome. Materials and Method:This study is consisted of 94 patients with poor obstetric history. Patients were evaluated in terms of the presence of cholelithiasis and urolithiasis in association with MTHFR polymorphism(s). Additional laboratory tests including homocysteine measurements were also performed. ROC analysis for assessing the performance of blood homocysteine level in predicting the presence of cholelithiasis and urolithiasis were also performed. Results:Patients were divided into three groups such as cholelithiasis group (n = 9, 9.6%), urolithiasis group (n = 18, 19.1%) and control group (n = 67, 71.3%). Groups did not differ in term of age and Beksac obstetrics index (BOI) which is "[living child+(pi/10)]/gravidity." The rate of the presence of MTHFR polymorphisms were 88.9% (8/9), 88.9% (16/18) and 43.3% (29/67) in cholelithiasis, urolithiasis and control groups respectively. Median homocysteine levels were found to be 13.1, 11.6 and 7.2 micromol/lt for the groups respectively. Statistically significant differences were found for MTHFR polymorphism rates and homocysteine levels (<0.001 for both). According to ROC analysis, 10.9 mcmol/L (88.9% sensitivity, 89.6% specificity) and 9.25 mcmol/L (83.3% sensitivity, 73.1% specificity) were determined to be cutoff values of homocysteine for cholelithiasis and urolithiasis respectively. Conclusion:More frequent MTHFR polymorphisms are observed in women with a clinical history of gall or renal stones. Thus, screening of these patients may be benefical for the approprate management of their subsequent pregnancies.