Pig and cattle follicular oocytes were stained by a counterstain- enhanced-fluorescence technique with Chromomycin A3-Distamycin A-DAPI (4,6- Diamidino-2-phenylindole) (CCD) as DNA-specific staining dyes. This method provided a clear visualization of the nuclear structures in pig and cattle oocytes. The cytogenetic stages found consisted of two major types; type I, with fine chromosomal filaments (bivalents), predominant in oocytes originating from small follicles (<1 mm); and type II, characterized by a pronounced clustering of chromatin, predominant in oocytes originating from large follicles (>2 mm). The majority of the porcine and bovine Giemsa stained chromomeres displayed DAPI bright and CMA3pale staining. Thus, they resemble mitotic G- and Q-bands in their staining behaviour.