1. Three lizard species (Callopistes maculatus, Gerrhosaurus major, and Varanus exanthematicus) were tested for their response to intraperitoneal injection of alcohol-killed Aeromonas sobria. 2. A paired experimental design, in which each animal received an injection of sterile saline and 1 x 10(10) A. sobria, was utilized. 3. C. maculatus demonstrated a statistically significant increase in mean selected body temperature (MSBT) after bacteria injection. 4. G. major and V. exanthematicus did not demonstrate a statistically significant increase in MSBT. 5. C. maculatus is the first lizard species outside of the family Iguanidae to exhibit a febrile response to bacterial pyrogen.