Many professional virtual communities (PVCs) have been unsuccessful due to the low willingness of members to participate in the communities. Thus, there is a need to understand what persuades individuals to participate in PVC activities. This paper develops an explorative model using the TAM as a foundation to examine the important determinants affecting the use of PVCs with the participation of one hundred and forty professionals from ResearchGate. Confirmatory factor analysis and structural equation modelling are used to evaluate the research model and analyze the data. The results show that the research model fits the data well and the structural model affirms that attitude significantly affects the intentional behavior of users. Perceived ease of use has a positive effect on attitude and perceived usefulness of users. Although perceived usefulness has a significant impact on the participants' attitude, it does not directly influence the intentional behavior of PVC users. Perceived security as a formative construct, complexity, and Internet self-efficacy are proven to be important drivers of perceived ease of use in PVCs. Moreover, the study results indicate that knowledge growth and collaboration have a positive and strong effect on the perceived usefulness of participants.