Background: For a subgroup of people with rheumatoid arthritis (RA) and severe disability, insight into their limitations is crucial for adequate treatment. Aim: To describe the extent and nature of functional limitations in people with RA and severe disability and to explore the associations of the extent of the functional limitations with patient characteristics, disease characteristics, and outcome measures. Methods: Baseline data of 215 participants in an RCT on the (cost-)effectiveness of longstanding physiotherapy were used. Functional limitations were assessed with the Health Assessment Questionnaire Disability Index (HAQ-DI). The total HAQ-DI including eight domain scores were calculated. Associations between high HAQ-DI scores (≥2, yes/no) and other variables were examined using the Student’s t-test or Chi-squared test where appropriate. Results: The participants (90% women, age 58.8 ± 12.8 years) had a mean HAQ-DI score of 1.7 ± 0.5. The majority (56%) showed a moderate-to-severe disability in all domains. Higher HAQ-DI scores seemed to be associated with advanced age, longer disease duration, unemployment, joint replacements, and outcomes for daily functioning and physical quality of life, but not with measures of disease activity. Conclusions: Our findings indicate that a comprehensive assessment of all areas of daily activities in this subgroup is necessary in order to provide appropriate (non-)pharmacological care.