Head Shaking Nystagmus(HSN) is latent spontaneous nystagmus and a sensitive sign of vestibular disorders. It is also very useful to discriminate between physiological and pathological spontaneous nystagmus. Authors evaluate HSN in 20 dizzy patients with eyes open in darkness(EOD), eyes closed(EC), eyes open under Frenzel glasses(EOF) and in different methods(active and passive) of head shaking. 1) HSN was present(positive) in 9 patients(45%). 2) 9 patient(100%) had HSN with EOD, 5 patients(55%) with EC and 5 patients(55%) with EOF. 3) Both passive and active head shaking induced HSN in 7 patient with EOD, 4 patients with EC and 4 patients with EOF. 4) 3 patients had type II HSN. 5) 4 patients who showed canal paresis on caloric test had type I HSN directed to normal side. 6) Among positive cases, 3 patients had spontaneous nystagmus which directed to the same direction as type I HSN and maximal slow phase of SPN increased on head shaking test.