A novel modified microstrip-fed ultrawide-band (UWB) printed Pythagorean tree fractal monopole antenna is presented. In this letter, by inserting a modified Pythagorean tree fractal in the conventional T-patch, much wider impedance bandwidth and new resonances will be produced. By only increasing the tree fractal iterations, new resonances are obtained. The designed antenna has a compact size of 25 × 25 × 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and operates over the frequency band between 2.6 and 11.12 GHz for VSWR <; 2. Using multifractal concept in modified Pythagorean tree fractal antenna design makes monopole antennas flexible in terms of controlling resonances and bandwidth. In this letter, the improvement process of the impedance bandwidth has been presented and discussed.