A non-invasive and non-destructive fluorescence technique developed recently for an in situ detection of melanomas has been applied for determining in vitro dysplasia and invasive carcinomas in the cervix uteri. The cervices uteri exhibit a fluorescence band with a peak at about 475 nm if excited with 365 nm. The fluorescence intensity increases concomitantly with the degree of dysplasia, ranging from 30 counts/100 ms (healthy) to approximately 200 counts per 100 ms (CIN 3). At the rim of a malignancy, the intensity is 250 counts/100 ms and higher and decreases towards the healthy region. In the tumor region, the intensity is about zero or very small, at the most. The naturally occurring chromophore being responsible for the fluorescence observed seems to be NADH.