The quest for quality fibre is the burning desire in the mind of every kenaf grower and this is a function of retting technology employed. This study was carried out to investigate the effect of alkali treatment on ribbon fibers and the effect of post retting alkalization on fibers. Four treatments (2.5%NaOH, 5.0%NaOH, 7.5%NaOH and Control) were applied at different soaking times (one and three hours). The ribbon fibers had significantly higher tensile strength and moduli than the non-ribbon fibers. In an hour soaking (1HS) interval, the ribbon fibers had significantly higher tensile strength and tensile moduli which increase with the increase in concentration of sodium hydroxide: 7.5% NaOH > 5.0%NaOH > 2.5%NaOH>Control. At 3HS, there was significantly lower tensile strength and modulus than that of 1HS even with the same treatment for ribbon fibers. The increase in concentration of sodium hydroxide resulted in higher tensile strength and moduli but these decreased as the soaking time increased. Unlike the ribbon fiber, at 1HS, the tensile strength and moduli were significantly higher than that of 3HS. Soaking kenaf fibers in NaOH solution for three hours had drastic reduction in its physico-mechanical properties. In both treatments, 2.5% NaOH had the highest tensile strength (58.88MPa and 45.30MPa for 1HS and 3HS respectively) while the Control had least tensile strength and moduli.