Background: Depression is a major cause of morbidity and cost in primary care patient populations. Successful depression improvement models, however, are complex. Based on organizational readiness theory, a practice inverted question marks commitment to change and its capability to carry out the change are both important predictors of initiating improvement. We empirically explored the links between relative commitment (i.e., the intention to move forward within the following year) and implementation capability. Methods: The DIAMOND initiative administered organizational surveys to medical and quality improvement leaders from each of 83 primary care practices in Minnesota. Surveys preceded initiation of activities directed at implementation of a collaborative care model for improving depression care. To assess implementation capability, we developed composites of survey items for five types of organizational factors postulated to be collaborative care barriers and facilitators. To assess relative commitment for each practice, we averaged leader ratings on an identical survey question assessing practice priorities. We used multivariable regression analyses to assess the extent to which implementation capability predicted relative commitment. We explored whether relative commitment or implementation capability measures were associated with earlier initiation of DIAMOND improvements. Results: All five implementation capability measures independently predicted practice leaders inverted question mark relative commitment to improving depression care in the following year. These included the following: quality improvement culture and attitudes (p =0.003), depression culture and attitudes (p <0.001), prior depression quality improvement activities (p <0.001), advanced access and tracking capabilities (p =0.03), and depression collaborative care features in place (p inverted question mark= inverted question mark0.03). Higher relative commitment (p inverted question mark= inverted question mark0.002) and prior depression quality improvement activities appeared to be associated with earlier participation in the DIAMOND initiative. Conclusions: The study supports the concept of organizational readiness to improve quality of care and the use of practice leader surveys to assess it. Practice leaders inverted question mark relative commitment to depression care improvement may be a useful measure of the likelihood that a practice is ready to initiate evidence-based depression care changes. A comprehensive organizational assessment of implementation capability for depression care improvement may identify specific barriers or facilitators to readiness that requires targeted attention from implementers.