In a retrospective study, a total of 120 ovarian cancer patients were paired in terms of staging, grading, patent age, and operative and cytostatic therapy. Half of the patients underwent radioimmunoscintigraphy for diagnostic purposes. From the point of view of possible adjuvant immunological therapy, we investigated to what extent patients with treated ovarian cancer benefit from the application of OC 125 in terms of survival time. In our study we have been able to show that at favorable stages (FIGO II) the patient benefitted more from a radioimmunoscintigraphy than at prognostically unfavorable stages (FIGO IV). Even within FIGO stage III we have been able to show, thanks to the large number of cases, that patients with an NED situation benefitted significantly more form radioimmunoscintigraphy in terms of survival than those with residual tumors. Throughout FIGO stage III, patients with radioimmunoscintigraphy showed significantly superior 5-year survival rates (p < 0.05) than those without radioimmunoscintigraphy. These data would appear to justify prospective studies to establish to what extent ovarian cancer patients benefit from an adjuvant application of OC 125 in terms of the 5-years survival rate and the relapse-free interval.