Nyandarua County of Kenya has been for a long time, manifested itself as one of the major food baskets in the country. This is because of its high and sustainable output in crop farming i.e., maize, Irish potatoes, wheat, and other horticultural crops like vegetables and fruits. However, this scenario has recently changed because the usual high crop output has not been forthcoming due to recent changes in climatic patterns where rainfall has become very unreliable and temperatures very extreme. In an attempt to adapt to this climate variability and its associated negative impacts on crop farming, smallholder farmers have tried to apply the greenhouse farming technology for them to be able to maintain and or improve the various crop output amid the climatic changes. The study aims to examine and assess the socio-economic determinants and constraints associated with this attempt of adaptation strategy. Using the primary data of 300 respondents (Smallholder farmers) in the County, the study adopted a logistic regression analysis model to associate the demographic, socio-economic, and constraints encountered by the smallholder farmers with the adoption of the greenhouse farming technology. The study results indicate that this adaptation strategy was reported by 25 out the 300 smallholder farmers (5.83%). The study results further suggest that financial constraints (27%) and lack of information (22.3%) are the major constraints preventing smallholder farmers from effectively adopting this adaptation strategy. However, the probability results of logistic regression analysis (68%) indicate that if properly adopted, the method can provide a solution to the currently reduced food shortages and increase food security among the smallholder farmers of Nyandarua County of Kenya.