Compositions of azathioprine oral suspensions are disclosed. Disclosed azathioprine oral suspensions may be used to administer azathioprine to subjects such as children and geriatric patients that may have difficulty in swallowing solid dosage forms. The disclosed azathioprine oral suspension may be used for treating autoimmune diseases such as rheumatoid arthritis, pemphigus, Behcets disease, autoimmune hepatitis, and inflammatory bowel disease, among others. According to an embodiment, an aqueous or non-aqueous vehicle may be used for azathioprine oral suspension. According to a different embodiment, sugar free azathioprine oral suspension may also be produced.
