Two field experiments were carried out at Sakha Agricultural Research Station, Agricultural Research Center, Kafr El-Sheikh, Egypt in 2017 and 2018 growing seasons, using Giza 94 and Giza 97 Egyptian cotton genotypes to investigate the effect of foliar application of nano titanium under three concentrations (25, 50 and 100ppm concentration of n-TiO₂) at two foliar application times (at the beginning of flowering and at the top of flowering) on yield, yield components and fiber quality. The experimental design was split plot design in three replicate. The obtained results indicated that titanium foliar treatments at the beginning of flowering recoded significant increase in yield characters except boll weight in both varieties compared to spraying at the top of flowering. Using 50ppm of nano titanium treatment improved significantly yield and yield component (No. of open boll/ plant, boll weight (g), seed index(g), seed cotton yield(g/plant), lint cotton yield (g/plant) and lint percentage% ) compared to the control, 25ppm and 100ppm of n-TiO₂ treatments, however this improvement in fiber properties was practically of low magnitude in both varieties along the two seasons. The Effect of growing season on yield traits was insignificant in most cases while it was insignificant on all fiber properties of the two varieties. Chemical analysis of the seed produced from 100ppm treatment indicated that the residue amount of titanium in the seed is lower than the permitted limits specified by World Health Organization in food and feed products.