In this letter, a dual-band fractal monopole antenna suitable for Long Term Evolution (LTE) standard is proposed. The antenna geometry is based on a perturbed planar Sierpinski fractal shape, whose geometrical descriptors are determined by means of a particle swarm optimization (PSO). The optimized antenna exhibits a good impedance matching within the LTE bands at 700 and 2600 MHz as well as a 24% size reduction with respect to a standard quarter-wave resonant monopole. The efficiency of the proposed antenna is assessed by means of both simulations and measurements.