Our objectives were to determine prevalence and intensity of gastrointestinal parasites of dead or euthanized emaciated moose in central and southern Sweden (n=50) and to assess parasite intensity as a major contributing factor in the poor condition of these moose. All animals were infected and most had gastrointestinal nematodes. Seven parasite species were found in the abomasa and 10 species were found in the small intestine. Coinfections were commonly found in the abomasum (Ostertagia antipini and Mazamastrongylus dagestanica) and in the small intestine (Nematodirella alcidis and Trichostrongylus capricola). Moose had many nematodes; the highest numbers were 224,400 and 11,760, in the abomasum and in the small intestine, respectively. Fourteen moose had more than 40,000 gastrointestinal nematodes (excluding large intestine nematodes represented by Trichuris spp. and Oesophagostomum venulosum). Additionally, a moderate prevalence (36%) of protostrongylid larvae (dorsal spine larvae) and a low prevalence (2–4%) of protozoal infections were identified at microscopic examination of feces. Adult moose had significantly more parasites than did subadults. The results did not show parasite load as a single or a major cause of the moose mortality, but they provided an update on the species composition of helminth parasites in moose in Sweden and illustrated the extreme infection intensities that free-ranging moose can have.