The aim of this study was to gain insight into the relationship of dog attachment with life satisfaction and the satisfaction of basic psychological needs in order to improve the scientific understanding of the area of the relationship between dogs and humans. The research was conducted on a sample of 431 inhabitants of Croatia (243 dog owners and 186 non-owners) with an average age of 30,61 years (sd = 11,673). Data were collected using an online survey and using the following instruments: Life Satisfaction Scale (Penezić, 2002), Basic Psychological Needs Scale (La Guardia, Ryan, Couchman, and Children, 2000) and the Adapted Lexington Pet Attachment Scale (Penezić and Levačić, 2012). Hierarchical regression analysis, ANOVA, t-test and non-parametric Kruskal-Wallis and Mann-Whitney U tests were used for statistical analyses. The designed model explained 59,5% of the life satisfaction variance with age, parenthood and need for competence and autonomy as significant predictors. Life satisfaction and satisfaction of basic psychological needs were not different between dog owners and non-owners. Statistically significant difference was found in need for relatedness between a group of highly educated people and people who have not completed a higher education degree in a way that people with a higher education degree have shown greater satisfaction of the need for relatedness. Satisfying the need for competence is more common in people living with a partner than in those not living with a partner. Research showed no significant interaction effects between marital status and dog ownership in competence satisfaction, nor the main effect of dog ownership. However, difference in the need for competence between persons who are not in a relationship and persons who are in a relationship or marriage was found, in such a way that persons outside the relationship or marriage had less satisfied need for competence. Research showed that people who are in a relationship are more satisfied with life than those who are not in a relationship, but it wasn't found in satisfaction of the need for relatedness with respect to marital status. Furthermore, no difference in attachment to dogs was found given the level of monthly income per household member nor between the group of parents and those participants who do not have children. However, women showed a higher attachment to dogs compared to men.