- Objectives To assess the importance of combined use of non-contrast computerized tomography (NCCT) and dynamic renal scintigraphy (DRS) in evaluation of patients with refractory flank pain in the emergency department. Methods The study involved 64 consecutive patients with refractory renal colic. All patients were evaluated with plain abdominal films kidneys, ureters and bladder (KUB), NCCT and DRS. We assessed the accuracy of different diagnostic procedures and their combinations; in addition, we determined their importance for different steps of evaluation. Results Urololithiasis was diagnosed in 76.6% (n = 49) of the patients. Twenty-nine percent of calculi were >4 mm. Surgical intervention were performed in 20 patients (40.8%). A combination of NCCT plus DRS yielded the greatest sensitivity (96%) in establishing final diagnosis, however clinical, laboratory and KUB data in combination with DRS, yielded greater specificity (93%) and PPV (97%). Sex (male), WBC (mean 10.2 × 103 ± 3.1) and KUB (calculus > 4 mm) were chosen in the three-step multi-variant analysis, while only male sex was found to be the strongest predictor (p < 0.056) of necessity to perform NCCT. In making decision for definitive treatment NCCT and DRS provided the most important information about stone size and obstruction (kappa = 0.734, p < 0.001 and kappa = 0.625, p < 0.001), while DRS was selected as the most important diagnostic procedure in the emergency department (kappa = 0.527, p < 0.001). Conclusions In the emergency department, DRS combined with the results of clinical investigation may indicate candidates for hospitalization with emergency intervention. Immediate NCCT must be strongly considered in men with WBC ≥ 10 × 103 and calculi > 4 mm on the KUB.