Background In patients seen in the emergency department (ED) with acute stone obstruction many risk factors that indicate need for urgent renal drainage are known. However, in patients discharged from ED without renal drainage factors that can minimize revisit to the emergency department are not fully identified. We evaluated SIRS (systemic inflammatory response syndrome) as a risk factor for urgent renal drainage and revisit to the ED in patients with acute stone colic during their ED visit. Methods Retrospective review was performed of patients presenting to a tertiary academic emergency department (ED) from an obstructing ureteral or UPJ stone with hydronephrosis confirmed on an abdominal and pelvic CT scan. Data evaluated over a 3-year period included stone size, presence of UTI, presence or absence of SIRS and other clinical variables as risk factors for urgent renal drainage and ED revisits. Results 1983 patients with urolithiasis were seen at the ED and 649 patients had obstructive urolithiasis on CT scan. SIRS was diagnosed in 15% (99/649) patients. 54/99 (55%) patients with SIRS underwent urgent renal drainage compared to 99/550 (17%) in non-SIRS patients. In a multivariate analysis SIRS was a predictor of urgent intervention compared to non-SIRS patients (odds ratio 4.6, p < 0.05). SIRS was also associated with increased risk for revisits to the ED (6.9% with SIRS vs. 2.4% with no SIRS, odds ratio 2.9, p = 0.05). Conclusions Presence of SIRS in obstructive urolithiasis patients was an independent risk factor of acute urologic intervention and revisits to the ED. A timely consultation with a urologist following discharge from ED for obstructive stone patients with SIRS who had no acute renal drainage may prevent revisit to the ED. Evaluation for SIRS in addition to other clinical risk factors should be considered while making management decision in patients with acute stone obstruction.