A 67-year-old woman on long-term chloroquine treatment for rheumatoid arthritis presented with dizziness and syncope. Although her medical history revealed no cardiovascular disease, complete atrioventricular block was detected by electrocardiography. Chloroquine was discontinued. Three days later, complete atrioventricular block spontaneously resolved to sinus rhythm. Cardiac complications associated with chronic chloroquine use are uncommon, nevertheless, there have been several reports on potential life-threatening rhythm disturbances and/or cardiomyopathy. In our case, atrioventricular block was associated with chronic chloroquine use. Cardiac evaluation with electrocardiography must be done for conduction disorders in patients using chloroquine for rheumatic diseases. Turk J Phys Med Rehab 2011;57:253-5.