Pakistan has achieved a breakthrough in farm production in recent years. It has been mainly due to increased acreage under high yielding varieties of foodgrains and other crops, improved irrigation supplies and the increased use of purchased inputs such as chemical fertilizers, pesticides and farm machinery. In this era of world wide food and fertilizer shortages it is important to identify as well as quantify the contribution of various farm inputs and particularly that of fertilizers to farm production. This would be useful in providing alternatives for increasing farm production in the short run under given technological conditions. This study was designed in an attempt to estimate the contribution of fertilizers and other farm inputs to the production of major crops in Punjab province of Pakistan. The crops included were Mexi-Pak wheat, local wheat, Basmati rice, IRRI rice, Jhonna rice, maize, cotton and sugarcane. The other objectives of the study were to compare the levels of fertilizer application among various farm categories, to determine the sources of financing fertilizer purchases and fertilizer supplies and to analyze the factors responsible for the inadequate use of fertilizers where that situation exists. The study was also designed to determine the influence of various agro-economic factors on the use of fertilizers in the province from time-series data. The primary data for the study were collected through a farm survey conducted in the fall of 1973. The data pertained to the cropping year 1972-73. In all, 192 farmers were interviewed. These were located in 16 villages in Gujranwa1a and Sahiwal districts. These two districts represent the typical wheat-rice and wheat-cotton cropping patterns; the major cropping patterns followed in the canal irrigated districts of the province. The production function has been the major analytical tool used in this study in the analysis of cross-sectional data. The ordinary least squares method of multiple regression was used to estimate the coefficients of production functions for the crops under study. This method was also used to analyze the impact of agro-economic factors on fertilizer use from the time-series data. The production function analysis suggests that the use of chemical fertilizers is highly profitable on Mexi-Pak and local wheat, Jhonna rice and cotton. There is considerable potential for increasing farm production of these crops through the increased use of fertilizers. From the analysis also, it appears that there is scope for increasing production of certain crops through increased use of labor. Higher farm output of sugarcane and maize was associated with the greater use of nitrogenous fertilizers. However, the analysis was not conclusive for Basmati and IRRI rice in this regard. The average per acre use of chemical fertilizers for the Mexi-Pak wheat, Basmati rice, cotton and sugarcane was higher on small farms as compared to medium and large farms. Urea was the most popular fertilizer with the farmers. Personal savings of the farmers and non institutional sources of credit were the major sources for financing the farmers' use of fertilizers. The commission agents and local dealers were cited as the chief suppliers of fertilizers by the farmers. High prices of fertilizers, lack of financial resources and the non-availability of fertilizers were the main reasons given by the farmers for the inadequate use of these materials. The analysis of time-series data suggests that the relative price of nitrogenous fertilizers has been quite important in influencing the use of these fertilizers in the province during the period of 1959-60 to 1972-73. Another important factor in this regard has been the increase in acreage under major crops, especially high yielding varieties of food grain crops. The use of fertilizers has been increasing over time. This has been probably due to increased information in the agricultural sector regarding the importance of fertilizers, and increased supplies and various market development activities of the private and public sectors.