A rapid and efficient procedure has been developed for the purification of α-glycerophosphate dehydrogenase from the tephritid fly Anastrepha suspensa. This procedure is applicable to the isolation of the enzyme from other tephritids. The A. suspensa α-glycerophosphate dehydrogenase is dimeric with a molecular weight of 70,000 and a subunit molecular weight of 35,000. The pH optimum of the enzyme is 7.0. The amino acid composition is compared with that of other α-glycerophosphate dehydrogenases. By means of the quantitative microcomplement fixation procedure the A. suspensa α-glycerophosphate dehydrogenase is compared immunologically to a variety of other tephritid and dipteran α-glycerophosphate dehydrogenases.