There is consensus among climate scientists that damages to agriculture from climate change will be disproportionately concentrated in developing countries whose economies are largely farm based. The effects on industrial economies will understandably be modest if long term aggregate global effects are taken into account. It is projected that in another twenty or thirty years global warming will actually benefit farm production in developed countries of higher latitude where temperatures and precipitations have not reached the critically damaging level that lower latitude countries have already attained. Scientists agree that there is no doubt that developing countries are going to feel the impact of climate change on their agriculture much sooner and more severely since they lack the technological knowhow and capacity to adapt. This consensus serves a timely warning to agronomists, breeders and economic managers of the developing world, in particular of South Asia, where local agriculture’s proneness to respond to climate change in the shape of falling output, floods and droughts has been evident for some years. It is time for the economic managers in Pakistan to engage them in preparing their farming communities for the challenges posted by climate change. This study attempts to add its bit to emphasizing the urgency of these forecasts. This dissertation seeks to examine, both theoretically and empirically, the impact of climate change on farm efficiency and household food security status in Rural Punjab Pakistan. These impacts have been examined at the farm level for a representative sample. Current study explores the climate change impact by using Stochastic Production Frontier Model. We also constructed household food security index by incorporating Technical and Profit efficiency as a food security indicator. Logistic regression was used to measure the impact of socioeconomic and weather shocks on household food security status. The outcomes of this study are indicative of a strong impact of climate change on the agriculture of Punjab, Pakistan. Increase in long run normal precipitation and temperature have significant effect on agricultural production and farm profit that fluctuates in direction as well as magnitude across quarters. Agricultural inputs like fertilizer, irrigation, pesticide sprays, labor man-days and tractor hours positively contributed to farm production. The incidence of weather shocks and socioeconomic characteristics of the farming households are important factors of technical efficiency at farm level. xiii Results are suggestive that the mean technical efficiency score of sampled farm households stands at 0.82 indicating that the average farm production could be increased by about 18 percent by using the existing technology more efficiently in the presence of climate change. The results of profit frontier also show that climate change has a substantial impact on farm profit. The quasi fixed inputs are positively and significantly related to farm profits while input prices contribute negatively to farm profitability. The average profit efficiency score turned out to be 0.72, suggesting that the average farm, by improving their efficiency can increase the profit up to 28 percent. Food Security Index (FSI) is also constructed using different indicators like per capita cereal production, cultivated area, number of food crop grown, animal adult units owned, assets value, health expenditures, technical and profit efficiencies which represent all three aspects for food security including availability, accessibility and utilization. The overall results show that 50 percent of the households were food insecure during the study period, while the remaining 50 percent were found food secure. We also attempted to find out the effects of socio-economic factors and climatic shocks that effect the status of household food security. The results revealed high incidence of food insecurity in the sampled districts that varies across cropping zones, cotton-wheat the least and rice-wheat crops zone the most food secure. Tenants and households headed by aged members were found more food insecure. Households having access to irrigation (from tube-well) were found more food secure than those who do not have this facility. Climatic shocks —precipitation and temperature deviations from the respective long run norms do play a significant role in determining the household food security status. The findings of present study are evocative of huge impact of climate change on the rain-fed areas of Punjab since these are water scarce areas depending on rain fall for cropping. Arguably, it is vital for the better performance of the agriculture sector to combat the impact of climate change more effectively through implementation of adaptation strategies.