The objective of the present study was to examine and compare the ability of Diploplastron affine and Entodinium caudatum to digest and ferment chitin. Cultivation studies showed that enrichment of the growth medium with this polysaccharide increased the ciliate count (P < 0.05). After 2 h of incubation of ciliates with chitin, a statistically significant increase in the percentage of individuals containing chitin particles was observed (P < 0.05), followed by a continuous decrease (P < 0.05) in this percentage. Enzymatic studies confirmed the ability of the examined protozoa to digest chitin. The chitinolytic activity of Diploplastron affine was 3.9 and that of Entodinium caudatum was 5.9 μmol N-acetyl glucosamine/mg protein/h. The production rates of volatile fatty acids from fermented chitin were 3.9 and 0.5 pmol/ciliate cell/h for Diploplastron affine and Entodinium caudatum, respectively.