BACKGROUND Poor sleep health is increasingly recognized as contributing to decreased quality of life, increased morbidity/mortality and heightened pain perception. Our purpose in this study was to observe the effect on sleep parameters, specifically sleep efficiency, in rheumatoid arthritis (RA) patients treated with anti-tumor necrosis factor alpha (anti-TNF-α) therapy. METHODS This was a prospective observational study of RA patients with hypersomnolence/poor sleep quality as defined by the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Study patients underwent overnight polysomnograms and completed questionnaire instruments assessing sleep prior to starting anti-TNF-α therapy and again after being established on therapy. The questionnaire included the ESS, PSQI, the Berlin instrument for assessment of obstructive sleep apnea (OSA) risk, restless legs syndrome (RLS) diagnostic criteria, and measures of disease activity/impact. RESULTS A total of 12 RA patients met inclusion criteria, of which 10 initiated anti-TNF-α therapy and underwent repeat polysomnograms and questionnaire studies approximately 2 months later. Polysomnographic criteria for OSA were met by 60% of patients. Following anti-TNF-α therapy initiation, significant improvements were observed by polysomnography (PSG) for sleep efficiency, increasing from 73.9% (SD 13.5) to 85.4% (SD 9.6) (p = 0.031), and 'awakening after sleep onset' time, decreasing from 84.1 minutes (SD 43.2) to 50.7 minutes (SD 36.5) (p = 0.048). Questionnaire instrument improvements were apparent in pain, fatigue, modified Health Assessment Questionnaire (mHAQ), and Rheumatoid Arthritis Disease Activity Index (RADAI) scores. CONCLUSIONS Improved sleep efficiency and 'awakening after sleep onset' time were observed in RA patients treated with anti-TNF-α therapy.