Autopsies and laboratory examinations of material from 24 Australian pelicans found sick or dead in southern coastal Queensland in 1977 to 1979 revealed dieldrin poisoning in 8 from the Brisbane region and botulism in 8 from Brisbane, Bundaberg and Gladstone. In those diagnosed as dieldrin poisoning, brain and liver samples contained 12.1 to 27.4 and 34.0 to 48.1 mg/kg dieldrin respectively. All of these birds were emaciated, 2 had convulsed and 1 had muscle tremors. Low and probably insignificant residues of DDE were detected in many birds. Type C botulism was confirmed in 4 of the 6 birds tested with specific antiserums. A large number of parasites including mites, lice, nematodes, cestodes, trematodes, coccidia and Sarcocystis sp were found but were thought to have had only a limited effect on the health of these birds.