['Maternal employment has been cited as a barrier to continued breastfeeding, yet there have been few studies identifying company breastfeeding support.', 'The study objectives were to develop and pilot an instrument that measures formal breastfeeding support in companies.', 'A survey of company breastfeeding supports was developed, based on the literature and expert review, and the survey piloted with Michigan-based companies.', 'Completion of the surveys and open-ended comments indicated survey items were generally well understood. In the study sample (N = 151), significantly more support was offered in companies having more employees as compared to fewer, and in companies from the health care versus all other sectors (P < .01). More support was also found in companies reporting requests for support, upper management combining breastfeeding and work, and a population that they felt likely to require breastfeeding support (P < .01). Few companies (3%) had written policies on breastfeeding or pumping at work. However, the majority of companies allow women to pump milk at the worksite (94%), and provide time (73%) and nonrestroom space to pump (78%). Fewer companies allow breastfeeding at the company (22%) or designate a room solely for breastfeeding or pumping (32%).'] Does development and piloting of an instrument that measure company support for breastfeeding?