OBJECTIVES In this study the relationship of serum homocysteine, vitamin B12, folic acid levels and peripheral vestibular dysfunction (PVD) was investigated. PATIENTS AND METHODS Forty-one patients (31 females, 10 males; mean age 57.34±14.3 years; range 12 to 80 years) who admitted to Baskent University Hospital Ear Nose and Throat Department between the dates of April 2005 - December 2007 with complaint of vertigo were prospectively analyzed and diagnosed using audio-vestibular test, at the same time serum homocysteine, vitamin B12, folic acid measurements was done from the blood samples of patients. The patients were divided into three groups as Meniere's disease, vestibular neurinitis, and benign paroxismal positional vertigo (BPPV) according to the diagnoses and serum homocysteine, vitamin B12, folic acid levels of patients were compared to normal values in and between groups. RESULTS Of the patients, 29.3% (n=12) were diagnosed with Meniere's disease, 36.6% (n=15) with vestibular neurinitis, and 34.1% (n=14) with BPPV. Serum homocysteine leves of patients were 12.42±3.56 umol/L, 11.32±4.14 umol/L and 10.72±2.95 umol/L (p>0.05) in Meniere's disease, vestibular neurinitis, and BPPV respectively; vitamin B12 levels were 371.58±141.35 pg/ml, 288.13±139.51 pg/ml, 352.14±150.41 pg/ml (p>0.05) respectively and folic acid levels were 8.76±3.2 umol/L, 10.63±6.59 umol/L, 8.8±3.18 umol/L (p>0.05) respectively. The values were similar in all patients. No statistically significant difference was found in and between groups comparing with normal values. CONCLUSION This is the first prospective study investigating the relationship of serum homocystein, vitamin B12 and folic acid levels with PVD. We found that there is no relationship of homocysteine, vitamin B12, folic acid levels with PVD.