Breastfeeding satisfaction is usually measured by how long a mother breastfeeds. Lack of another method to measure the mother's evaluation of breastfeeding has been a barrier to breastfeeding research. This study tested validity and reliability of the Maternal Breastfeeding Evaluation Scale (MBFES), a new tool which measures mothers' satisfaction with breastfeeding. The sample consisted of 73 women who attended breastfeeding classes in a midwestern hospital. MBFES scores were significantly correlated with the length of time mothers intended to breastfeed (r = .31) and the length of time they breastfed (r = .49), which supports validity. Correlation coefficients for the scale and subscales, .83, .73, .76, and .78, respectively, indicated acceptable internal consistency among items in the scale. These findings support reliability and validity of the MBFES for clinical use.