The present study was carried out to study the effect of treatment with three doses (5,10 and 15 min) of laser irradiation and evaluate the induced variability on some quantitative characters of the two Egyptian cotton cultivars Giza 92 and Giza 94. The trial was conducted at Sakha Experimental Station, Agricultural Research Center, Kafr El-Sheikh, Egypt during three growing seasons from 2014 to 2016. The results indicated that the laser irradiation decreased the mean performance of yield and yield components for Giza 92, while the Giza 94 variety exhibited increase for yield and yield components. no effect was found for the fiber quality of Giza 92, while better fiber quality was obtained for Giza 94 except for fiber strength which was reduced with the mutagen treatments in M₁ generation. The treatment with laser irradiation increased the variability for most studied traits. The results of kurtosis indicated that most of cases were less than 3 indicated that the variability of plants were distributed as platykurtic so, the individual plants are unconcentrated around the means. Heritability estimated showed high values for boll weight (more than 50%) in M₁ 5 and 10 min and M₂ 15 min , as well as for number of bolls per plant , seed and lint cotton yield per plant, lint percentage and  fiber fineness in M₁ of Giza 92, fiber length in all generations of Giza 94. Low values of broad senses heritability (less than 30%) were found for boll weight of Giza 94 in treatment 15 min of M₁ and M₂, as well as in treatment of 10 min in M₂ for Giza 92. The fiber fineness exhibited low heritability value for Giza 94, while Giza 92 exhibited high values of heritability. The relationship between the yield and boll weight was significantly positive for control treatment, and between the yield and lint percentage in M₂ and M₃ of treatment 10 min for Giza 92, while Giza 94 exhibited insignificant correlation between yield and lint percentage and fiber fineness. Giza 92 exhibited insignificant correlation between yield and both fiber strength and fiber length, while the cultivar Giza 94 revealed negative and significant correlation in M₁ for the treatment 5 and 10 min, as well as 15 min in M₁ and M₂ between the same traits.