Painful diabetic neuropathy (PDN) is the main pathogenic factor in diabetic foot problems. The present study aimed to predict the quality of life (QoL) and self-care behaviors based on self-compassion, mental pain, and emotional expressivity in patients with PDN. This was cross-sectional research and the study population included patients with PDN referred to the diabetes clinic in Yasuj City in 2022. A total of 171 participants were selected using convenience sampling methods. Demographic form, The World Health Organization Quality of Life-BREF (WHOQOL-BREF), Orbach Mikulincer Mental Pain Scale (OMMP), self-care questionnaire, self-compassion scale, and emotional expressiveness scale were used to collect data. Data analysis was carried out using SPSS-25. Participants were male and female in 49 (28.7%) and 122 (71.3%) of cases, respectively. The results showed a significant relationship between QoL and self-care behaviors with self-compassion, mental pain, and emotional expressivity (P <
0.01). Also, self-compassion, mental pain, and emotional expressiveness were significant predictors of QoL and self-care behaviors (P <
0.05). Therefore, it is suggested to pay attention to self-compassion, mental pain, and emotional expressivity in psychological interventions to improve QoL and self-care behaviors of patients with PDN.