The,design of modified Yagi-Uda arrays with additional parasitic elements in the area of the radiating dipole, acting either as reflectors or directors, is presented. The genetic algorithms are employed, and various objective functions concerning gain, front-to-back ratio, and the latter combined with desired input impedance, are examined. Comparisons are made among the modified and conventional Yagi-Uda configurations for different weighting coefficients of the fitness functions. The modified Yagi-Uda array outperforms the conventional Yagi-Uda array, because it achieves higher performance standards over an extended bandwidth around 2.4 GHz.