Aim: The objective of this study is to determine tomographic measurement parametres that are effective on spontaneous passage (SP) of ureteral stones in patients who will undergo unenhanced multidetector computed tomographic examinations (MDCT). Material and Method: The patients who presented with complaints of renal colic to our clinic during 2013-2015 were retrospectively evaluated. The medical files of 813 patients were reviewed and the medical records of 331 cases who had undergone CT were examined. A total of 217 patients whose stone size was less than 10 mm were included in the study. The patients whose stones passed were included in Group 1, and those whose stones did not pass spontaneously were included in Group 2. Data about age and gender of the patients, location, laterality, history of spontaneous stone passage from the ipsilateral side, ureteroscopy, shock wave lithotripsy (SWL), anteroposterior (AP) diameter of the renal pelvis, diameter of the stone as measured on coronal and axial planes, stone volume, and average thickness of the renal parenchyma were evaluated. Parametres effecting passage of the stone were statistically analysed. Results: The mean age of the patients (female, n=152, and male, n=65) was 42.3 years. The patients had upper (n=73) and lower (n=144) ureteral stones. The median diameter of the renal pelvis (17.2 mm), stone diameter on the coronal plane (6.1 mm) and the axial plane (4.6 mm), and thickness of the renal parenchyma (20 mm) were measured. Statistical analysis revealed that the location, volume, diameter of the stone on the coronal and axial planes were influential factors on spontaneous stone passage. In logistic regression analysis, only the location of the stone and its diameter on the coronal plane were found to be independent effective factors on spontaneous stone passage. Discussion: In our study based on data retrieved from MDCT, the location and size of the stone were found to be independent factors affecting spontaneous stone passage. However, a surprising result is that the AP diameter of renal pelvis and renal parenchymal thickness, both of which are factors important for urologists, were not effective on SP.