Virtual worlds (VW) have paved a new and important channel for workplace collaborations. However, analysts have noted that several organizations that made a strong entrance into using VW as a nouveau channel for communication and collaboration are stepping back due to limited user response. Motivated by this fact, we propose a trust-theoretic ‘virtual world collaboration model’ for collaborations in virtual worlds. The model, grounded in literature on ‘technology adoption’ and ‘trust’, theoretically examines the role of trust in motivating users for using this rich virtual communication medium for collaborations. Results establish the important roles of perceived social presence and perceived structural assurance for fostering user trust in VW. Further, results also indicate that user trust is significantly related to both extrinsic and intrinsic motivations, which in turn influence the behavioural intention to use the VW. Implications for research and practice are discussed.