NOVELTY - A process for racemization of enantiomerically enriched 3-carbamoylmethyl-5-methylhexanoic acid (I) involves: i) treating the enantiomerically enriched 3-carbamoylmethyl-5-methylhexanoic acid with hydrochloric acid at a temperature of 45-70 degrees C to form 3-isobutyl glutarimide (XVII); ii) hydrolyzing the compound 3-isobutyl glutarimide with aqueous sodium hydroxide solution at 20-45 degrees C to form racemic 3-carbamoylmethyl-5-methylhexanoic acid (I); and iii) isolating the racemic compound (I).    USE - For racemization of enantiomerically enriched 3-carbamoylmethyl-5-methylhexanoic acid used as intermediate in the preparation of (S)-3-(aminomethyl)-5-methylhexanoic acid (claimed) i.e. (S)-Pregabalin exhibiting anti-seizure activity and useful for treating, among other conditions, pain, physiological conditions associated with psychomotor stimulants, inflammation, gastrointestinal damage, alcoholism, insomnia, and various psychiatric disorders, including mania and bipolar disorder; and for treating neuropathic pain and as an adjunct therapy for partial seizures.    ADVANTAGE - The method provides efficient environment friendly process for racemization of enantiomerically enriched 3-carbamoylmethyl-5-methylhexanoic acid. The method provides improved process for racemization of (S)-isomer of 3-carbamoylmethyl-5-methylhexanoic acid, eliminates the drawbacks of the prior art process and avoids the use of base and high boiling solvents and employs a more robust process which is convenient and cost efficient. The improved process ameliorates the drawbacks in the prior art for racemization of (S)-isomer of 3-carbamoylmethyl-5-methylhexanoic acid by avoiding the use of base and high boiling organic solvents by carrying out the process in environment friendly solvent water, which makes the process robust, operator friendly and techno-commercially viable for industrial production. The method is economical and industrially practicable; avoids use of piperidine base and organic solvent; and avoids use of high boiling solvent.