arvae of the sheep blowfly Lucilia sericata (Meigen) were reared on various mixtures of puréed liver, agar, brewer's yeast and trypsin, in order to develop a simple, sterile, tissue-based diet. Growth and survival rates of larvae reared on a sterile 1:1 mixture of puréed liver with 3% Bacto agar equalled or exceeded those of larvae reared on raw liver. The addition of yeast and/or trypsin to the medium was of no additional benefit. This sterile, homogenous, tissue-based substrate offers a simple, convenient, inexpensive growth medium for rearing larvae for maggot therapy, and for testing the effects of various chemicals and dietary constituents on necrophagous insect larvae. It may be useful, therefore, in studies of myiasis, forensic entomology, and toxicology. This rearing medium also has the advantage that it can be stored for many months at room temperature without progressive decomposition or offensive odour.