Sleep disturbances and problems are increased in ankylosing spondylitis (AS). But much is not known in a quantitative way about sleep problems and effect of treatments on AS. This study is aimed first, to investigate sleep disturbances in AS and secondly, to evaluate the effects of anti-TNF treatment on SD in AS. One hundred seventy-one (Female/male: 90/81) AS patients fulfilling modified New York criteria and 86 (F/M: 56/30) age- and gender-matched controls without inflammatory diseases were included into the study. Demographic data and disease activity and treatments were recorded using The Bath Ankylosing Spondylitis Functional Index (BASFI) and The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The Medical Outcomes Study (MOS) Sleep Questionnaire was used for evaluating sleep and problems of sleep. AS patients had higher sleep disturbance scale (SDS) and sleep problem index (SPI) II scores. Group A (patients using NSAID and/or DMARD, 53.2% of patients) had higher BASDAI and BASFI compared with Group B (Patients using anti-TNF treatments) (4.29 ± 2.38 vs. 2.46 ± 2.32, p < 0.001; 1.95 ± 2.15 vs. 0.93 ± 1.31, p < 0.001, respectively). Whereas Group A had higher scores of SDS, awaken short of breath or headache, somnolence, and SPI-II than controls, none of the sleep parameters were statistically different between patients on anti-TNF treatments and controls. BASDAI was positively correlated with SPI-I, SPI-II, SDS, and somnolence scale. AS patients had increased sleep problems and disturbances compared with controls. Anti-TNF agents improve significantly these problems. Sleep problems are significantly correlated with the disease activity.