Chromosome analysis is an important task to detect genetic diseases. However, the process of identifying chromosomes can be very time consuming. Therefore, the use of an automatic process to detect chromosomes is an impor- tant step to aid the diagnosis. The proposed work develop a new approach to automatize the segmentation of chromosomes, using an adaptive thresholding combined with fuzzy logic. The proposed method is evaluated using the data- base from CRCN-NE, which has 35 images. Results showed that the proposed approach compared with state of the art techniques obtained better segmenta- tion results, with sensitivity and specificity values of 91% and 92%, respectively.