Abstract Background and Aims Kidney transplantation (KT) is considered the most effective treatment for end-stage renal disease (ESRD), and it significantly contributes to enhancing the quality of life and extending the survival of patients with ESRD. After kidney transplantation, the early and heavy use of immunosuppressants and glucocorticoids can affect the recipients' immune status to varying degrees, increasing the risk of postoperative infections caused by a wide range of pathogens. Thus, the prevention and management of infectious diseases are major factors contributing to improved outcomes in kidney transplantation. Protein-energy wasting (PEW) is commonly observed in uremic patients, and it may persist even after they have undergone kidney transplantation (KT). And PEW is a significant factor in the progression of chronic kidney disease (CKD). Providing appropriate dietary guidance and intervention is essential for enhancing the immune status of recipients, promoting a positive nitrogen balance in the body, minimizing infections, and safeguarding graft function. This study aimed to investigate the relationship between daily protein intake (DPI) and postoperative infections at 3 months post-transplant, which may establish a foundation for the early postoperative protein intake regimen, reducing the incidence of postoperative infections, and improving the early prognosis of kidney transplantation. Method This is a retrospective observational study. 176 kidney transplant recipients (KTRs) who underwent kidney transplant in West China Hospital from December 2021 to June 2022 were included and followed up regularly. 24-hour urine urea data were collected at months 1 and 3 post-transplant to calculate their DPI. These KTRs were further divided into two groups according to the recommended DPI for KTRs by the 2021 Practice Guidelines for the Nutritional Management of Chronic Kidney Disease, namely high intake group (Group 1, with DPI ≥ 1.4 g/kg·d, n = 66) and low intake group (Group 2, with DPI < 1.4 g/kg·d, n = 110). Occurrence of hospitalization and postoperative infections within 3 months were recorded. Multiple logistic regression was utilized to analyze the association between DPI and early postoperative infections at 3 months post-transplant. Results Mean DPI levels at month 1 post-transplant were 1.58 ± 0.22 g/kg·d in Group 1 and 1.02 ± 0.31 g/kg·d in Group 2, respectively (P < 0.05), this huge difference in DPI between the two groups continued to month 3. There was no significant difference in age, gender, pre-transplant body mass index (BMI), dialysis type and time, donor type, or the ratio of delayed graft function (DGF) between the two groups. There was a statistically significant difference in the percentage of hospitalization between the two groups during the postoperative period of 3 months (P = 0.027). Pneumonia was the most common reason of hospitalization after transplantation, followed by urinary tract infection. The results of multiple logistic regression analysis showed that higher DPI in the early post-transplant period was a protective factor for infection after kidney transplantation. Conclusion In the early post-transplant period, consuming higher levels of dietary protein may reduce the risk of infections and complications, and help preserve the function of the transplanted kidney.