Psychosocial environment at work is now considered a health determinant. The National Population Health Survey (NPHS) of 1994-95 is the first study in which psychological demands and decision latitude at work were measured in a random sample of the Canadian population. However, psychometric properties of the scales used in NPHS to measure these factors are not known. The objective of the present paper was to evaluate some validity parameters of the scales used in the NPHS by comparison to the original scales recommended by Karasek to measure these factors. Results of the current study support the validity of the decision latitude scale. However, validity of the psychological demand scale is more limited.