The study aimed to evaluate disease knowledge, perceived susceptibility and compliance behaviors of post-kidney transplant patients as well as assess relationship between disease knowledge, perceived susceptibility and compliance behaviors. A descriptive cross-sectional study conducted on 153 post-kidney transplant patients from March to June 2024 at Outpatient Department of Cho Ray hospital. The result showed that the majority of respondents have a lack of knowledge regarding medication and lifestyle change post kidney transplantation. While perceived susceptibility of respondents were at a fair level. Majority of respondents has a low level of perception regarding barriers to adherence and susceptibility to transplant rejection, while they have a good level of perception regarding benefits of adherence to treatment with immunosuppressive medication. Compliance behavior of post kidney transplant adults was at a good level. Majority of respondents had good compliance behavior regarding medication, while exercise and psychological adaptation was the lowest level of compliance behavior. There are positive relationships between Compliance behaviors and disease knowledge (r = 0.49, p < 0.001); perceived susceptibility (r = 0.45, p < 0.001) and perceived susceptibility plays a partial mediating role between knowledge and compliance behaviors and the mediating effect accounted for 31% of the total effect of disease knowledge on compliance behavior. The study also indicated that educational level (ꞵ = 0.93, p = 0.020), duration of transplant (ꞵ = 0.20, p = 0.012) are predictive factors of compliance behavior among post – kidney transplant patients. Educational interventions targeting both knowledge and health beliefs, particularly for older individuals, could improve adherence to treatment and overall health outcomes.