Abnormalities in the structure of chromosomes cause fetal deaths or developmental disorders. Chromosome analysis is a method used to diagnose many chromosomal disorders such as Down syndrome. Metaphase images are needed for chromosome analysis. Objective selections must be made during the acquisition of these images. Selecting of non-analyzable images could directly affect the results of chromosome analysis. In this study, a filter was developed that automatically detects analyzable metaphase images. The developed filter was used with the motorized microscope table and the analyzable metaphase images were detected. After expert evaluation on the results obtained, the average success rate of the filter was calculated as 98.9%. The filter performed an average run time of 76 milliseconds per square.