Background: Kidney transplantation is the treatment of choice for most patients with end-stage renal disease (ESRD), however, compliance to the recommended therapeutic regimen is critical for a positive prognosis. Several factors affect patient's compliance these factors include, social and economic factors, health care system-related Factors, condition-related factors, therapy-related factors and patient-related factors. Aim: This study aimed to assess factors affecting patient's compliance toward therapeutic regimen post kidney transplantation. Design: A descriptive explorative design was used. Setting: it was conducted at the outpatients' clinics at Urology and Nephrology center-that affiliated to Mansura University, Egypt. Subjects: A purposive sample of 101 adult patients from both sexes were recruited for this study. Tools: three tools were used in the study; I) Patient's interview questionnaire including two parts, 1) socio-demographic data of the patient. 2) patient's health history. II) Patient's compliance assessment tool. III) Factors affecting patient's compliance assessment tool. Results: the study revealed that, the majority of renal transplant recipients had a partial compliance toward therapeutic regimen post kidney transplantation. Furthermore, the most common factors affecting patients' compliance were, therapy-related factors rated the highest dimension followed by condition- related factors and patient- related factors respectively. Conclusion: the majority of the studied patients had a partial compliance with therapeutic regimen. Furthermore, many factors were affecting patients` compliance such as; therapy-related factor, condition-related factors, patient-related factors, social and economic factors and health care system-related factors. There was a highly significant relation between total compliance score and total factors.  Recommendations: educational nursing guidelines should be conducted for patients to improve their compliance and intensive assessment of factors affecting patient's compliance should be done periodically to identify their needs which help in the plan to improve their compliance.