Background: Comorbidity is prevalent in people with chronic kidney disease (CKD) and this status burdens one's health literacy skills to understand about their health, make decisions, and to adhere with treatment.

Objectives: To examine health literacy in people with CKD and comorbidities.

Design: A cross-sectional study was conducted between November 2018 and April 2019.

Participants: Convenience sampling recruited 367 adults with CKD and at least one comorbid disease.

Measurements: Data were collected using the 9-domain Health Literacy Questionnaire. Demographic and clinical characteristics were also collected. Charlson Comorbidity Index calculated comorbidity status. Parametric tests were used to distinguish health literacy between various groups.

Results: Participants' average age was 58.8 years, 54.7% had CKD Grade 5, 72.5% had a severe comorbidity index (≥6), and nearly 40% were on haemodialysis. Lower health literacy proportions were found in domains related to Healthcare providers' support (58.3%) and Appraisal of health information (38.4%). Lower levels of education, income, or living in rural areas were each significantly more likely to contribute to lower health literacy levels (range 4–7 domains). Greater comorbidity severity was also significantly associated with lower health literacy in two domains.

Conclusion: People with CKD had difficulties in various health literacy domains primarily related to communication and critical appraisal. These domains can be improved by healthcare professionals and changes in hospital policies. Due to frequent contact with patients in kidney services, renal clinicians have a crucial role in ensuring greater communication occurs as this will better assist patients to understand their healthcare needs.