Two series of Ak samples, one collected at random from ten different sources at the flowering stage (July), and the other from Peshawar at various stages of maturity, were examined for a number of physical characteristics. A number of different methods of retting were investigated to get at the optimum procedure. The anatomical characteristics, length, diameter and ratio of length to diameter of the ultimate fibers were evaluated. The effects of stage of harvesting, methods of retting, different levels of relative humidity, and anatomical characteristics on the strength of the filaments were examined.