The initiative for exploiting the commercial potential of natural gas as feedstock and fuel by planning NGFF for producing urea fertilizer in the mid-1950s was based on a single gas field in what is now Bangladesh. The use of natural gas as a fuel in Chhatak Cement Factory in 1960 replaced imported coal and thus began the era of cleaner fuel for industries in Bangladesh. The commissioning of NGFF in 1961 for producing urea, a proven source of nitrogen nutrient especially for rice, marked the beginning of the green revolution in Bangladesh. The consumption of natural gas during the past decade up to 2001 shows that the power sector consumes approximately 45 %, fertilizer sector 35 % and the other sectors 20 %. There are now 53 production wells capable of producing more than 36.8 million standard cubic metres (Mm3) per day of gas from 12 gas fields. In 1972, there were only two ammonia-urea complexes having a combined installed capacity of 446,000 tonnes (t) of urea per year. Today the country has seven ammonia-urea complexes (six in the public sector and one in the private sector) with a total installed capacity of 2,895,700 t of urea and 1,886,700 t of ammonia per year. All seven complexes are of the grass-roots type. In the various complexes consumption of natural gas used as feedstock per unit production of ammonia or equivalent quantity of urea is not significantly different irrespective of the age of the plant or technology used, but the consumption of natural gas as fuel burned in the primary reformer (PRF), auxiliary boilers (utility boilers) and captive power plants is influenced by the way process heat and waste heat from PRF and power plants are recovered, utilized and integrated in the plant energy requirement system. In the larger plants the steam system is integrated by considering convenience of generation and utilization as motive power, heating medium as well as process feed. Since natural gas in Bangladesh is rich in methane, the ammonia plant has to be oversized by a few per cent to produce the required carbon dioxide for the rated urea production. This leads to additional natural gas consumption per unit urea production and obviously this is a penalty in a competitive market. Modifications and revamping of the complexes have been carried out from time to time. Most process modifications have required sizable capital investment. When these complexes were designed and equipment procured, today's concepts of energy efficiency were in their formative stages. More efficient motors, pumps, turbines, compressors, boilers, furnaces, etc. could have been procured, but the issues of provenness and reliability were of paramount importance as against savings from being more energy-efficient. The performance of these complexes is discussed in the context of utilization of stream days, capacity utilization and consumption of natural gas (both for process and fuel) per t of urea produced. The economic performance is not discussed, because the sale price of urea and depreciation to be charged are fixed by the government for the six plants owned by BCIC, while KAFCO either exports its urea produced or sells it to BCIC at world market price. The sale price of urea fixed by the Government is today about US$ 40 below the price offered by KAFCO. NGFF remained the lone major consumer of natural gas up to 1967, consuming about 87 % of the annual gas production. In 1968, other sectors such as power, domestic and commercial started to use gas as fuel. With the commissioning of UFFL in 1970 the share of gas used by the fertilizer sector further rose. With the commissioning of a new urea complex there has been a clearly identifiable rise in the gas demand, indicating the low annual demand growth in Bangladesh. It is only from 1984 that the power sector's natural gas consumption exceeded that of the fertilizer sector. Today the connected gas load of the seven urea complexes is 7.85 Mm3/day and the annual consumption with all plants operating is about 2.55 Gm3. The natural gas industry through its association with the fertili er sector has been able to standardize the gas intake stations for bulk consumers, metering stations and maintenance/operation of gas transmission system. Even though the power sector has a connected gas load of about 18.4 Mm3/day, all energy demand projections consider the fertilizer load an equally important category, and this is the reason why the fertilizer industry is considered to be a separate sector. The demand for natural gas by the fertilizer sector in the next two decades will, however, not increase significantly. Even if the country needs to produce an additional 1 million t of urea, the gas requirement would be an additional 1.42 Mm3 if plants such as NGFF, UFFL and PUFF are shut down. The fertilizer sector based on natural gas has provided the necessary life support for the development and growth of the gas industry since the first discovery of natural gas in the country. Urea fertilizer together with natural gas based electricity is today recognized as the cornerstone of the country's food security and political stability.