Background: Paternal involvement in pregnancy has been recognized to have an impact on new-born’s outcomes and only recently got under the spot light of mental health perspective. The aim of this study was to test differences in paternal involvement in pregnancy, perceived stress and relationship quality regarding complications in pregnancy and pregnancy duration (gestational weeks) in the last trimester of pregnancy. The role of personality traits (neuroticism and extroversion), relationship quality satisfaction and perceived stress in prospective father’s perception of pregnancy involvement were examined. Subjects and method: One-hundred forty-three primiparus couples in the last trimester of their pregnancy participated in the study. Prospective fathers completed a booklet with questionnaires including The Quality of Marriage Index, The Perceived Stress Scale, Eysenck Personality Questionnaire and Partner’s Involvement in Pregnancy Scale. Prospective mothers completed only Eysenck Personality Questionnaire and questions on pregnancy complications and demographics. Results: The prospective fathers showed high involvement in their partner’s pregnancies, elevated levels of perceived stress and high relationship quality. There were found no differences in the above named variables regarding complications in pregnancy and pregnancy duration. Higher involvement of prospective fathers was related with older age, lower male neuroticism and higher female extroversion, better relationship quality and lower perceived stress. Conclusion: The findings demonstrate that prospective father’s involvement in pregnancy is supported with psychological factors, namely personality traits, quality of relationship and perceived stress. These results should lead to target interventions that can modify and improve fathers’ involvement perspective and promoting a couples mental health during pregnancy: thus clinically important for promotion of healthy prenatal behaviour and decrease in mothers’ emotional distress.