Two cultivars of bread wheat {Triticum aestivum L.) showing significant differences in stomatal frequency on the adaxial surface of the flag leaf blade, were hybridized. Transgressive segregation for stomatal frequency was observed in the F2 generation and selections were made for high and low stomatal frequency. In the F9 generation two selections had significantly higher frequencies than the higher parent. Heritability for stomatal frequency based on parent-progeny regression were 42 % (F3-F4) and 81 % (F4-F5). Stomatal frequency was negatively correlated with the flag leaf blade area, mesophyll cell size and grain size, however, exceptions were observed.