The task of segmenting cell nuclei in microscope images is a classical image analysis problem. The accurate nuclei segmentation may contribute to development of successful system which automate the analysis of microscope images for pathology detection. In this article we describe a method for semi-supervised training of fuzzy logic engine. The fuzzy logic engine is applied to connect a set of parameters proven to be important for nucleus segmentation. In addition each parameter for itself is detected using a set of fuzzy logic rules. We present results of nuclei segmentation using fuzzy logic set of rules.