Background: The pace of diffusion of BIM (Building Information Modelling) use is considered to increase with governmental initiatives in which public clients in countries like Finland, Singapore, United Kingdom, and Sweden begin requiring BIM as a part of the project delivery. Currently, larger contractor firms use BIM to a certain extent. However, BIM use by mid-sized contractor firms (that is, firms with 50-500 employees that can successfully compete with larger contractors on projects costing a maximum of 50 million Euros) is relatively unknown. Hence, the aim of the paper is to explore current use and perceived constraints and driving forces of BIM-implementation with respect to mid-sized contractors. Methods: A mixed method approach was applied, and data was collected through an interview study and a survey involving chief executive officers or their closest sub-ordinates in mid-sized contractor firms in Sweden. The survey was based on a technology-, organization-, and environment framework that is used in information systems research to study the use of interorganizational information systems. The total population of firms in the survey corresponded to 104. The study presented the preliminary results based on 32 answers (with a 31% response rate). Results: Fifty-eight percent of the surveyed respondents stated that they had been involved in a project in which BIM was used in some manner. The most commonly used application included visualization, which also facilitates coordination and communication. The biggest perceived constraints involved partners that did not use BIM, lack of demand from clients, and the absence of internal demand in the company. With respect to the two last obstacles, significant differences existed between users and non-users. The most common perceived driving forces included the fact that BIM is perceived as a means to follow technical development and that BIM provides competitive advantages to the company. Conclusions: It is concluded that the main driver responsible for BIM-implementation is mainly determined by an individual's subjective positive or negative evaluation of BIM, instead of external pressure from clients and partners or by the internal capacity and knowledge to use BIM.