In this paper a novel algorithm is proposed for cancelling the Power Line Interference (PLI) and its harmonics from Electromyography (EMG) signals using an adaptive IIR Laguerre filter. This algorithm is independent of power line information and reference noise for Laguerre structure is constructed mathematically. The Least Mean Square (LMS) algorithm is used to optimize the filter weights. This Laguerre filter consumes significantly less computational load than adaptive FIR filters and also has better stability than IIR filters. Our simulations and practical experiments indicated that proposed structure has improved Signal to Noise Ratio (SNR) up to 10dB which is significantly more than adaptive FIR filters.