A process for preparation of protriptyline hydrochloride from 5-dihydrobenzocycloheptatriene of formula (1) by coupling with chloropropyl alcohol in the presence of excess n-butyl Lithium in tetrahydrofuran under inert atmosphere, followed by preparation of mesylate derivative of formula (3) and finally the nucleophilic displacement of the mesylate group by reacting methylamine solution in methanol to give protriptyline free base of the formula (4). Also the present process reveals the hydrochloride salt formation and purification of the same to give pure pharmaceutical grade protriptyline hydrochloride with impurities less than 0.1% w/w.