Having an infant requiring care in a neonatal intensive care unit (NICU) is challenging for parents. The aim was to investigate the effects of the Family Health Conversation (FamHC) model on self-reported mental health, family wellbeing, and family functioning in parents of infants requiring mechanical respiratory support during NICU care. This interventional study included 147 parents (72, intervention group; 75, control group). All participants received a study-specific questionnaire at three time points. The intervention trended toward positive effects on mental health, family wellbeing, and family functioning. However, all measurements showed considerable variation, and the estimated effects were not statistically significant at the 0.05 level. Regardless of the intervention, mental health symptoms decreased over time, whereas family wellbeing and functioning remained stable. To conclude, although the intervention trended favorable for all outcomes, no significant differences were observed between groups. Potential effects might be better identified using qualitative methodology or self-reporting measures in a larger sample.