Purpose: The purpose of this study was to examine the validity of a single item scale by comparing a single item scale of health related quality of life to subscopes of the multi-item scales in the Medical Outcome Study Short Form-36 (SF-36), and Minnesota Living with Heart Failure Questionnaire (MLHFQ). Method: The data from 103 patients with heart failure were analyzed. The statistics program SPSS 12.0 used for descriptive statistics. Results: Significant correlations were found between the single item scale and subscopes of SF-36, for physical functioning (r= .42), role physical (r= .22), general health perception (r= .46), vitality (r= .40), social functioning (r= .20) and mental health (r= .51), but not for body pain (r= .12) and role emotional (r= .06). Physical (r= -.41), emotional (r= -.49) and total scores (r= -.49) of MLHFQ were significantly related to the single item scale. Conclusion: The single item scale of health related quality of life showed low to moderate correlation with multi-item scales. Even though the single item scale was correlated with several subscopes of multi-item scales, the correlation was not high, so we have to use caution when using the single item scale instead of multi-item scales.