The aim of this work was to determine the role of toxoplasmosis in the pathology of pregnancy among women in the Lublin province, and simultaneously the attempt to evaluate the correlation between three diagnostic methods: Frenkel's intradermal test, Sabin-Feldman's dye test and complement fixation reaction. 396 women were examined and 332 simultaneously submitted to serological and allergical investigations. In 64 cases the investigations were only carried out with the complement fixation and intradermal tests. The highest number of positive results was obtained by the intradernal reaction, i. e. 33.8%, the lowest by the complement fixation reaction 8.3%. The dye test gave 10.6%. The conformity of the results for all three tests amounts to 56.7% (225 cases). In the remaining cases (171) the conformity of results between the individual tests was studied, and so: for the complement fixation and the dye tests it amounted to 15.6%, for complement fixation and Frenkel's intradermal tests to 12.5%, for the dye test and Frenkel's intradermal test - 6.7%. The remaining 9,5% fell on the unconformity between the results of the complement fixation reaction and Frenkel's intradermal test. The highest percentage of infections has been observed in the group of premature deliveries; that is 56.6%. To this group belongs also a relatively great number of stillborn children and children with development defects. In the group of women who suffered abortion the percentage of positive results is the lowest – 21.05%. The percentage of positive results is almost identical in the goup of women who were not suspected of toxoplasmosis and in the group where this suspicion existed (32.1%-34,7%). An exact anamnesis concerning the pregnancies of 241 women (multiparae) has shown that the number of abortions in the group of women with positive results is by 50% higher than in the group with negative results. The number of nonviable fetuses is by 2.9 times higher and the number of premature deliveries by 30% higher. The number of infants with development defects is 3 times higher in the group of women who were infected with toxoplasmosis. The number, however, of stillborn children with positive results amounts to 3,8%, while in the group of women with negative results to 5.6%. In cases of habitual abortion, premature delivery or development defects the possibility of toxoplasma infection in the mother should be taken into consideration and laboratorial investigations carried out, such as: complement fixation reaction, Sabin-Feldman's dye test and Ftenkel's intradermal test. A positive results of even one of the serological test in comparison with clinical observations makes an anti-toxoplasmosis treatment unavoidable.