The present invention relates to modified release pharmaceutical compositions of methylphenidate or salts thereof. In particular, the present invention relates to a modified release pharmaceutical composition comprising plurality of components exhibiting both immediate and extended release of methylphenidate or salts thereof. The composition may provide extended and specific release of methylphenidate or salts thereof to achieve therapeutically effective plasma concentration over a period of 12 hours to treat attention deficit disorders when administered to a patient in need thereof. The invention also includes process of preparing such composition.
