Irrigation is one of the most important ingredients of the Green Revolution technology, which took place in early 70’s. With out irrigation water, desirable results, of the new agricultural technology cannot be achieved. NWFP is mainly a mountainous region and its agriculture is characterized by low yield per unit and poor application of required inputs. About 54% of the total cultivated land still depends on rainfall which is scantly. Keeping in view the wide scope and importance of irrigation for enhancing agricultural output the present study was initiated. The study aims to analyze the existing situation of tube well irrigation and to pinpoint the main causes of slow diffusion of tube well technology in NWFP. Moreover, an attempt was also made to examine the role of extension agent in the adoption and diffusion of tube well technology. This study was based on primary as well as secondary data. The universe of the study consisted of the whole NWFP. Multistage sampling method was used to select a required sample, from four districts randomly selected. The number of respondents interviewed from district Charsada were 92, from DIK 70, from Malakand 68, and 61 respondents from district Nowshera, hence the total sample size was 291. The selected respondents were grouped into three categories namely small (146), medium (81) and large (64). The average size of land holding was 8 acres for small, 16 for medium and 92 acres for large farmers. Fragmentation seriously constrained tube well installation in the study area. The rate of tube well installation was less than 10 per year on average, thus there is clear justification and wide scope for future expansion if tube wells in the study area. Tube well irrigation not only enhances agricultural productivity, but socio-economic condition of the farmers was also improved. The role of government and NGO’s remained insignificant, because 288 respondents installed tube wells by themselves. The soil of the study area was found suitable for tube well installation. Moreover, water table was cost effective for the respondents in the study area. The discharge capacity of tube wells in the study area ranged from 2” to 4”. Majority of the respondents (96%) did not test the quality of water and soil. The overwhelming majority of the respondents (266) could not get loan. Extension services were heavily criticized and their role in the adoption and diffusion was negligible. The linkages among farmers, extension workers, and research institutes remained weak and poor. Small farmers were more prone to operational problems. The main operational problems were lack of spare parts, shortage of power, lack of skilled labour, and frequent load shedding of electricity. Almost all the sample respondents reported inadequate and untimely availability of inputs. The main factors responsible for late adoption and slow diffusion of tube well technology are; size of land holding, poor financial condition, lack of technical know how, topography, lack of power supply (electricity/diesel), inefficient and ineffective extension staff, imperfect market and policy negligence of the government. As a policy matter farmers (particularly small farmers) need to be encouraged to install tube wells, through the provision of soft loans and technical assistance.