The present report deals with 413 ureteric stone attacks treated in hospital and followed up to six years. If there was no need for emergency surgery, the patients were treated conservatively and followed with renograms on an out-patient basis after the initial evaluation. Stones up to 6 mm in diameter were passed during a reasonable time in 92% of the cases. In some cases an endoscopic procedure preceded the passage. Many of the larger stones were also passed. Nine of the 16 uretero lithotomies in the series were performed due to compromise in renal function during the follow-up period; these resulted in no permanent damage. Only two cases of slight renal damage occurred in the conservatively treated group of patients. There were no deaths or nephrectomies. The data suggest that modern follow-up facilities allow the safe adoption of very conservative attitudes in the treatment of ureteric stones.