In this paper a full composite fractal antenna, having a modified Sierpinski fractal antenna with 50-Ω microstrip line, used for dual band wireless applications. The S11 parameter and radiation characteristics of the antenna design indicate that a Sierpinski fractal antenna with circular slot having Dual Band frequency bandwidth from 3.8 GHz to 4.4 GHz and 4.8 GHz to 5.4 GHz to covering 5.2 GHz for C-Band and X-Band wireless applications in 3.8 GHz– 14 GHz frequency range. The proposed antenna is fed by a 50-Ω microstrip line and designed on a low cost FR4 substrate having dimensions 96 (L) ×72 (W) × 1.5 (t) mm3 with □r=4.9 and tan δ= 0.025. The antenna shows acceptable gain with nearly omni-directional radiation patterns in the frequency band.