In this paper we presented some aspects of current research on the possible application of new cancers in the study developed in recent years a branch of science ? fractal geometry . There are many definitions of a fractal . Developer of fractal geometry Mandelbrot this term geometric shapes found in nature ( different from the figures of Euclidean geometry ) . There are two types of fractals ? nonstochastic ( not found in nature ) and stochastic occurring widely in nature. Fractal figures due to their high complexity fills the space in a greater degree than the figures of Euclidean geometry . The degree to which a figure fills the space , is determined by the fractal dimension , which is the most important parameter characterizing the fractality of the figure. The fractal dimension is estimated using various methods. The most commonly used are the compass and boxed . Is also used methods: probabilistic field - circuit mass scaling and others. Fractal dimension is determined using computer programs that make measurement on a properly processed ( digitized ) images of examined structures . From the point of view of the theory of deterministic chaos, fractals are the result of processes chaodynamicznych . One of the processes that seem to laws of deterministic chaos is carcinogenesis . So the question arises as to whether the mathematical methods can be used to evaluate microscopic images of cancer. Presented in this paper the results of various studies on both the creation of mathematical models of tumor growth , material taken from tumor tissues , experimental studies on cancer cells and tumor development studies conducted in vivo leads to the conclusion that the determination of the fractal dimension can be a valuable adjunct diagnosis of cancer. Fractal dimension characterizes the test object , but not always sufficient to uniquely identify . Perhaps it will be used in the staging of cancer.