Reverse transcription and polymerase chain reaction (RT/PCR) with primers specific for tyrosinase allow for a new method of early detection of individual melanoma cells in peripheral blood. Using this test the effect of chemo- and chemoimmunotherapy on the spread of early micrometastatic cancer cells has been evaluated. No significant correlations have been found between RT/PCR results on the one hand and stage of disease, a kind of the therapy protocol used and usage of the therapy as an adjuvant or palliative on the other hand. Thus, although the RT/PCR test for detection of circulating individual melanoma cells might help in identification of minimal residual disease in some patients, it has no application for routine staging of more advanced disease and in monitoring the response to therapy.