The present invention provides an improved process for preparation of Escitalopram of formula (I) or its pharmaceutically acceptable salt, solvates or hydrates thereof formula (I), (III): via formation of hydrobromide salt of 4-(4-(dimethylamino)-l-(4-fluorophenyl)-l- hydroxybutyl)-3-(hydroxymethyl) benzonitrile of formula (III) to purify the compound of formula (III).
