This paper assesses whether tractor investment is a rational and profitable decision for farmers using firm investment theory and tractor owner survey data collected in 2013. Under erratic rainfalls, timeliness of farming operations is critical for farmers. Based on the hypothesis that owning a tractor and hiring tractor services are not necessarily perfect substitutes for farmers with relatively large farm sizes, this paper assesses whether mechanization services can be profitable for the private sector in Ghana. It particularly addresses whether farmer-to-farmer service provision is a viable alternative to current programs, which should be promoted by policymakers for scaling up agricultural mechanization in the country. This paper suggests that owning a tractor for service provision alone, as in the Agricultural Mechanization Service Enterprise Center (AMSEC) model, is unlikely to be viable. On the other hand, service provision is profitable for numerous tractor-owning farmers when timeliness benefits which they derive from tractor use on own farms are taken into consideration, although these benefits are not always observable. Alternatively, using tractors to provide maize-shelling services has helped owners overcome the seasonal constraints on tractor use. Private operations of tractor-owning farmers suggest that AMSECs could be viable if they extend the range of services offered to smallholders to include services such as maize shelling and productivity-enhancing land preparation techniques. Increasing the efficiency of public interventions on the use of farm machines can enable the private sector to scale up agricultural mechanization within the short to medium term, leading to the development of the service rental market for the benefit of smallholder farmers in the country.