This study investigates the effect of three key firm characteristics (diversification, size, and age) on road freight companies’ early adoption of alternative fuel vehicles (AFVs). While previous studies have identified the determinants of the adoption intention of AFVs, a gap in the literature is research into firm characteristics and the early adopters of AFVs. Because early adopters play an important role in the diffusion of innovation, it is imperative to fill this gap. Based on a survey of 156 Swedish road freight companies and logistic regression analyses, we report that firm size and diversification affect the early adoption of AFVs. In addition, the partial impact of the importance of driver comfort and payload capacity on early adoption of AFVs has been reported. Other factors, including purchase price, fuel cost, and truck refueling efficiency, were not found to discriminate early adopters of AFVs from those who had not yet adopted AFVs. These findings imply to policymakers that the current instruments in use in Sweden, including the greenhouse gas mandate and the relatively high taxation on diesel fuel, have led to the adoption of AFVs by larger road freight companies. For vehicle producers aiming to scale up the production and sales of AFV, the findings suggest the benefit of targeting diversified and larger road freight companies in the first place. © 2024 The Author(s)