Objectives: To investigate the disease pattern at National Hospital of Dermato,-Venereology (NHDV) and to compare the diagnostic quality of the lower Dermato-Venereological Units to that in NHDV. Material and Method: a cross-sectional study based on 639 patients at NHDV from Aug,2012 to Aug,2013. Result: Base on ICD10, in NHDV, Papulosquamous disorders contributed the highest prevalence (21.1 percent), the lowest prevalence is urticaria and erythema. The difference in diagnosis from lower DV units to NHDV was 42,9 percent
from OPD to IPD of NHDV was 16,1 percent. The groups that normally be misdiagnosed were infections of the skin and subcutaneous tissue, skin cancer and pre-cancerous skin diseases. The Northwest area of Vietnam is the one that had highest prevalance of misdiagnosis.