This study assesses the impact of major climate variables (temperature and rainfall) on crops productivity across four agro ecological zones of Pakistan. The crops selected were rice, wheat, maize, cotton and sugarcane. The study used panel data from 1991 to 2010 taken from Federal Bureau of Statistics (1982-2009), Khyber Pakhtunkhwa Development Statistics (2010), Punjab Development Statistics (2011), Statistical Pocket Book of the Punjab (2011) and Pakistan Meteorological Department Islamabad. Analysis has been made through applying pooled least square estimation techniques namely fixed effect model and random effect models. The results revealed that the effect of climatic variables on crops yield varied across agro climatic zone due to differences in their climate condition. Temperature and rainfall were the important determinants affecting crops productivity across agro climatic zones of Pakistan. Further in Indus Delta (Zone I) increase in rainfall favored rice and sugarcane productivity and affected wheat productivity adversely. Also increase in three different temperatures ranges (maximum, minimum and average temperatures) positively affected wheat, rice and sugarcane yields. In Northern irrigated Plain a (Zone IV) increase in three different temperatures ranges (maximum, minimum and average temperatures) increases wheat, rice, cotton and sugarcane productivity and negatively affected maize yield. Similarly increase in rainfall favored maize, wheat, rice, cotton and sugarcane yield in Zone IV. Increase in rainfall and three different temperatures ranges (maximum, minimum and average temperatures) had a positive impact on VIII major crops i.e. wheat, maize and sugarcane yield in Northern irrigated Plain b (Zone IV). In Wet Mountains (Zone VI) increase in temperature favored wheat and maize productivity while increase in Kharif season rainfall has affected negatively the maize yield. Similarly in Northern Dry Mountains (Zone VII) increase in three different temperatures ranges (maximum, minimum and average temperatures) had a positive impact on wheat, rice and maize yield while increase in rainfall adversely affected maize yield. Wheat productivity has been impacted more in Northern Irrigated Plain a (Zone IV) by average temperature and in Northern Dry Mountains (Zone VII) by rainfall than the other zones. Rice productivity has been impacted more in Dry Mountains (Zone VII) by average temperature and in Indus Delta (Zone I) by rainfall than the other zones. Sugarcane productivity has been impacted more by average temperature and rainfall in Indus Delta (Zone I) than zone IV. Maize productivity has been impacted more by average temperature and rainfall in Northern Dry Mountains (Zone VII) than the other zones. Finally the study recommends proper mitigative and adaptative strategies to enhance the positive and lessen the adverse impact of climate change on crops productivity across agro climatic zones of Pakistan. Supervisor:- Dr Anwar Hussain