Abstract. We propose a method for the diagnostics of skin neoplasms, based on the analysis of the changes in the autofluorescence spectra in the near infrared range. The autofluorescence was excited by means of the laser radiation with the wavelength 785 nm for ex vivo and in vivo studies with subsequent exponential approximation of its spectrum. The quantitative and qualitative criteria for the neoplasm type differentiation by the change of the curvature and the rate of decrease of the approximating curve are found. It is shown that the proposed approach allows the diagnostics of malignant melanomas with the accuracy of 88.4% for ex vivo studies, and 86.2 % for in vivo ones.