The purpose of this study was to examine the mediating effects and sequential double mediation effects of basic psychological needs and grit on the relationship between father and mother attachment and career attitude maturity in university students. A survey was conducted with 342 students from four-year universities across the country. Correlation analysis, structural equation modeling, and mediation analysis were performed. The results were as follows. First, father and mother attachment, basic psychological needs, grit, and career attitude maturity showed positive correlations. Second, basic psychological needs had a significant mediating effect on the relationship between father and mother attachment and career attitude maturity. Grit showed a mediating effect in the relationship between father attachment and career attitude maturity, but not in the case of mother attachment, indicating a difference. Third, basic psychological needs and grit demonstrated a significant sequential double mediation effect in the relationship between father and mother attachment and career attitude maturity. Based on these results, the study discussed its implications, limitations, and suggestions for future research.