257 patients suffering from cervical cancer (stage I and II according to FIGO classification) were included in this retrospective study. All of them underwent radical surgery between 1978 and 1987, including pelvic lymphadenectomy. In addition to conventional follow-up procedures, isotope nephrograms (ING) were performed as a routine measure. ING curves reflect renal function and serve as a highly sensitive qualitative parameter of urine flow. It may therefore be used as indirect indicator of pathologic changes in the small pelvis, such as recurrent disease. Follow-up period was between 3 and 10 years. Chi-square test was used to determine the probability of correlation between the evidence of pathologic ING-curves (yes/no) and a) lymph node status (pos/neg), b) patients, who underwent adjuvant radiotherapy (yes/no), or c) patients, who revealed recurrent disease (yes, no). All of the subgroups showed significant positive correlation. Pathological ING curves appeared a) in 61% of patients having a positive lymph node status (n = 66, p = 0.001), in 88% of patients, who developed recurrent disease (n = 56, p = 0.001) and in 44% of patients, who received adjuvant irradiation therapy (n = 131, p = 0.05). The high degree of sensitivity of ING concerning urinary tract obstruction seems to justify the routine use of this method in the follow-up of these patients. It should help to identify impaired renal function in good time.