Aims We aimed to assess the level of non-adherence and poor illness perception among rheumatoid arthritis (RA) patients. Additionally, we examined their associations with clinical indicators and outcomes. Methods This was a cross-sectional study conducted using data collected at the time of patient enrolment in the Pakistan Registry of Rheumatic Diseases (PRIME) registry. A wide range of clinical variables was studied. To measure adherence, we used the Urdu version of the General Medication Adherence Scale (GMAS), which has recently been validated in RA patients. A Brief Illness Perception Questionnaire (BIPQ) was used to measure illness perception. Results The data of consecutive 320 RA patients were reviewed. Thirty-six percent of the cohort (n=116) was noted to have non-adherence. On multiple logistic regression analysis, a significant association of non-adherence was noted with moderate-to-severe stress (odds ratio {OR}: 1.85, confidence interval {CI}: 1.04-3.2), DAS-28 scores (OR: 1.83, CI: 1.52-2.21), Health Assessment Questionnaire (HAQ) scores (OR: 1.77, CI: 1.07-2.92), and deformed joint counts (OR: 1.30, CI: 1.15-1.46). Additionally, non-adherence due to "patient behavior" had a significant association with the male gender (OR: 0.48, CI: 0.26-0.87), unemployment (OR: 1.82, CI: 1.07-3.10), and stress at home (OR: 2.17, CI: 1.35-3.49). Twenty-six percent of the cohort (n=86) was noted to have the most negative illness perception, and on multiple logistic regression analysis, it was significantly associated with male gender (OR: 0.24, CI: 0.11-0.53), age of onset of arthritis (OR: 0.96, CI: 0.94-0.99), and worse HAQ scores (OR: 3.7, CI: 2.2-6.1). Conclusions Important adverse factors contributing to non-adherence and negative illness perception highlighted in this study were stress at home, female gender, and younger age of patients.