The present invention relates a composition comprising Diclofenac and salts thereof wherein Diclofenac or its salts are present in an amount of 25-200 mg. The composition is suitable for the parenteral administration through intramuscular, intravenous route; also for oral, dermal, subcutaneous, cutaneous, nasal, ocular drops, as rectal suppository, vaginal pessaries, intra-articular, and otic delivery. The invention also provides compositions comprising a combination of Diclofenac and other drugs. The invention further provides a method for preparing said composition.