Abstract Background and Aims People with chronic kidney disease (CKD) often experience a high healthcare workload in the form of medication management, contacts with healthcare services, and other tasks. Co-existing health conditions can increase healthcare workload, with mental disorders generating additional workload alongside physical conditions. We hypothesised that mental disorders in people with CKD would be common and that healthcare workload would be elevated for people with mental disorders. Method Data were used from the Secure Anonymised Information Linkage Databank: primary care data for people living in Wales, UK, with linkage to hospital records. We studied adults over the age of 18 with CKD G3-5 not on kidney replacement therapy. We defined “mental disorder” as any primary care-recorded diagnosis of anxiety, depression, eating disorders, schizophrenia, and/or bipolar disorder. We estimated healthcare workload by quantifying visits to accident and emergency (A&E), days spent in hospital during emergency admissions (general hospitals and psychiatric hospitals), number of outpatient clinic appointments, locations of clinic appointments, and number of long-term medications prescribed. We estimated associations between mental disorders and healthcare workload using negative binomial models, making adjustments for age, sex, diabetes, ischaemic heart disease, smoking status, and socioeconomic deprivation. Results Of 173 388 people with CKD, mean age was 77 years, 54 537 (31.5%) had one or more mental disorder and 20 374 (11.8%) had two or more. Over a median follow-up period of 5.5 years, people with CKD and mental disorders spent a median 1.9 days in hospital (interquartile interval [IQI] 0.0 to 14.7) compared to people with CKD without mental disorders: 1.0 (IQI 0.0 to 9.9) days. People with CKD and mental disorders attended a median of 2.6 clinics (IQI 1.0 to 5.5) compared to people with CKD without mental disorders: 2.3 (IQI 0.8 to 4.9). The presence of any mental disorder was associated with more days spent in hospital: adjusted rate ratio (aRR) 1.58 (95% confidence interval 1.54-1.62), more A&E attendances: aRR 1.37 (1.35-1.39) and more clinic appointments: aRR 1.13 (1.11-1.14). The association with hospital days was strongest for people with eating disorders: aRR 3.70 (2.50-5.49). People with any mental disorder attended a similar number of locations for clinics than those without mental disorders: median 2 for both groups (IQI 1 to 3). However, people with schizophrenia, bipolar disorder or eating disorders attended more locations: median 3 (IQI 2 to 4). People with mental disorders took more medications (median 9: IQI 6 to 13) than those without mental disorders (median 7: IQI 4 to 10). Conclusion Mental disorders are common amongst people with CKD and healthcare workload is greater for people with than without mental disorders. Although a proportion of the increased healthcare workload might be expected (such as people taking medications for their mental health), the additional days spent in hospital is a notable finding. This may reflect problems with how these people experience healthcare and it is likely to have an impact on their quality of life. Targeted work is required to understand the specific healthcare needs of people with CKD and mental health disorders.