Since most kidney transplantations in Japan are performed on the basis of living donors, after-transplant outcomes should achieve optimum results, overcoming participants' possible reduced adherence. This study investigated the association between the Japanese version of the Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT-J) and outcomes, one year after the patient's living kidney transplant (LKT). The prospective cohort study was undertaken at Tokyo Women's Medical University Hospital from January 2020 to July 2021, with a one-year follow-up period. The SIPAT-J assesses 18 psychosocial risk factors: (A) Patient's Readiness Level and Illness Management (SIPAT A), (B) Social Support System Level of Readiness (SIPAT B), (C) Psychological Stability and Psychopathology (SIPAT C), and (D) Lifestyle and Effect of Substance Use (SIPAT D). The evaluators, a psychiatrist and three clinical psychologists, conducted an independent, blinded application of the SIPAT-J using participants' medical records. The study focused on physical composite outcomes, psychiatric outcomes, and non-adherent behaviors. The participants were 173 LKT recipients (median age (IQR) 51 (38-59)); 67.1% were male, and 67.1% were employed. The median (IQR) SIPAT scores were SIPAT A [7 (5-9)], SIPAT B [7 (5-9)], SIPAT C [2 (0-4)], SIPAT D [3 (3-4)], and SIPAT total [20 (16-23)]. The physical composite outcome was 25 (14.5%), psychiatric outcome 9 (5.2%), and non-adherent behavior 17 (9.8%). SIPAT C (odds ratio [OR]=1.34, 95% confidence interval [Cl]=1.06-1.72, p=0.02) was significantly associated with the psychiatric outcome. SIPAT B (OR=1.49, 95% Cl=1.12-1.98, p=0.01) and SIPAT total (OR=1.13, 95% Cl=1.03-1.24, p=0.01) were significantly associated with non-adherent behaviors. There was no significant association between the SIPAT and physical composite outcomes. This study is the first to examine the association between SIPAT and physical and psychiatric outcomes one year after LKT, controlling for follow-up periods and factors other than SIPAT. Comprehensive psychosocial assessment before LKT and early identification of factors that may negatively affect transplant success can allow targeted interventions to be implemented and increase the likelihood of favorable recipient outcomes.