Abstract: Deforestation has emerged as one of the major concerns of the world community as significant environmental impacts are attributed to it. The plainly observed association between population increase and deforestation in most of the developing countries has deepened the concern on deforestation. An analysis on forest cover and population of Kokrajhar district of Assam in India over the period 1977-2007 revealed a strong inverse relationship between the two (correlation co-efficient = -0.99). Population growth rate was steadily decreasing in the district, while deforestation rate was found to fluctuate. During the period, the district lost 38% of its forest cover that existed in the beginning of the period. Despite of declining growth rate of population of the forest area, deforestation was taking place at an alarming rate. Estimation of forest cover of the district by the Forest Area Change Model of Food and Agricultural Organization indicated that if deforestation continues with the recent rate, and population growth rate remains more or less same, the district, in the next three decades, would loss 43.5% of its forest cover that was available in 2007. By the beginning of nineties of the current century, when the population density is expected to be about 492 per sq km, the vegetation of possible deforestable area of the district would be almost completely cleared. The results of the analysis were found to conform to FAO theories of deforestation. However, the association between population and deforestation was found to be weakened towards the last decade.