Crude T. spiralis larval antigens often cross-react with antibodies to other parasites (for instance Toxocara canis) in the ELISA test. The crossreactivity of the sera is probably due to the presence of phosphocholine (PC)-specific antibodies to antigens found in the inner layer of the cuticle, in the haemolymph, genital primordium and glycogen aggregates T. spiralis larvae. The anti-PC response following infection with T. spiralis occurs earlier than the antispecific antigens response. The above data suggest a possibility that some results of immunoenzymatic examination for trichinellosis may be false positive. The necessity of WESTERN blot verification of weakly positive results in the ELISA test seems to be obvious. There is a need to improve serological diagnosis of trichinellosis by applying alternative tests that would aid an early diagnosis of the infection such as those for circulation parasite antigens or parasite DNA.