Azamethiphos (CAS No. 35575-96-3) was evaluated for developmental toxicity. Twenty pregnant rabbits (strain was not reported) per group were treated with 0, 2.5, 7.5, or 15 mg/kg/day of the test material by oral gavage on days 6-18 of gestation. Food consumption and body weight gain were reduced in dams at 7.5 and 15 mg/kg/day. At 15 mg/kg/day, significantly decreased body weight, increased numbers of unossified phalangeal nuclei of the fore and hind-limbs, and unossified 5th sternebrae were observed. These observations were related to maternal toxicity. No embryotoxic or teratogenic effects were observed.