A controlled release pharmaceutical composition comprising Milnacipran or pharmaceutically acceptable salts thereof and hydrophobic release controlling agent. The composition releases 90% of the total amount of Milnacipran or pharmaceutically acceptable salts thereof between 8 to 20 hours when dissolution is carried out in 900 ml 0.1N HCl, USP apparatus Type I (Basket) at 100 rpm for 2 hrs, followed by 900 ml Phosphate buffer pH 6.8 USP apparatus Type I (Basket) at 100 rpm. A process of preparing a controlled release pharmaceutical composition comprises: a) preparing a first layer comprising i) melting hydrophobic release controlling agent and Milnacipran or pharmaceutically acceptable salts thereof in it ii) cooling followed by sieving the melted mass to obtain granules and iii) lubricating the granules and b) preparing a second layer comprising granules which comprises hydrophobic release controlling agent and optionally Milnacipran or pharmaceutically acceptable salts thereof.