In this study, we interpret codependency as a dysfunctional pattern of relating to others, and based on this approach, we hypothesized an association with negative forms of dyadic coping, relationship problems and life satisfaction. A total of 246 Hungarian participants (167 females, 79 males), aged 18–72 years (M = 35.3, SD = 11.6) completed our online survey including measures of codependency, dyadic coping, perceptions of relationship, and life satisfaction. In our cross-sectional research, the Spann-Fischer Codependency Scale (SF-CDS), the Dyadic Coping Inventory (DCI), the Shortened Marital Stress Scale (MSS-R), and the Satisfaction With Life Scale (SWLS) were used. Correlational and pathway analyzes were applied to confirm our hypotheses. Codependency was associated with negative dyadic coping, while we found no measurable influence on positive dyadic coping. Individuals with higher codependency rated both their own and their partner’s negative dyadic coping more pronounced, while at the same time they characterized their relationships as more problematic. Structural Equation Modelling proved that codependent attitudes, along with the emergence of negative dyadic coping forms and perception of relationship problems, reduce a person’s life satisfaction. Overall, it can be stated that the more codependent the participants were, the more negative their own and partner’s behaviour was perceived in stressful situations and the more problematic their intimate relationship was found to be. Our results support the idea that codependency is a specific, largely stable attitude that determines a person’s perception and behaviour relating to others.