This study is a compilation of many of the ova or larva of parasites encountered in laboratory animals. In the interest of brevity, the parasites are separated according to similar hosts rather than species of animal. Realizing that this collection is by no means complete, we feel that it is necessary to provide researchers with some method of identifying parasites of the laboratory animals most commonly used. At the present time a variety of texts must be consulted to identify the many parasite ova infrequently observed. We believe this review ill prove valuable as a training aid for new laboratory and veterinary technicians as well as for research veterinarians.