A total number of 24 local Turopolje pigs (TP) reared in outdoor area with predominantly forest vegetation were monitored for 20 weeks (from July to December 2015) with the aim to determine the prevalence of swine gastrointestinal parasites after exposure to natural infection. At the beginning of the trial, pigs were dewormed with 300 μg of doramectin per kg of body weight (Dectomax®, Pfizer; 1 ml/33 kg). Faecal egg counts (FECs) were determined after 14 and 20 weeks in individually obtained samples separately for large roundworm (Ascaris suum) and other gastrointestinal parasites (Oesophagostomum spp., Strongyloides spp. and Hyostrongylus spp.). The results of coprological examination showed that main gastrointestinal parasites in outdoor reared TP are helminth species with strongyle-type eggs and coccidian Eimeria spp. In typical hot and dry season, more than 14 weeks’ period after antiparasitic treatment is required for infection and development of sexually mature parasite stages and eggs excretion in the faeces. These results may be important in designing of integrated gastrointestinal management practices for TP in traditional outdoor production systems, and generally useful for more sustainable management of this endangered breed in future.