Current measures of the working alliance tend to emphasize the degree of agreement or collaboration between patient and therapist about therapeutic tasks and goals. There are, however, both theoretical and empirical grounds to suggest that the degree to which patient and therapist are able to constructively negotiate disagreements about tasks and goals is another important dimension of the alliance. The present study outlines the preliminary development and evaluation of a measure to operationalize this dimension. This measure, the alliance negotiation scale (ANS), is a 12-item patient self-report instrument. Exploratory factor analysis and expert ratings informed the development of the scale, which consists of two distinct factors that demonstrate good internal consistency. Correlations between these factors and the working alliance offer preliminary support for its construct validity. A working version of the ANS is presented and the need for further validation is discussed.