In this work, a novel tunable attenuator is presented which is based on few layer graphene flakes. The attenuator is formed of a microstrip line with metallic grounded vias on either side separated from the microstrip line by few layer graphene flakes. The insertion loss of the attenuator can be tuned by changing the bias voltage applied to the graphene flakes. It is shown that the reflection from the attenuator is minimized and its bandwidth is doubled with an increase in the tunable range. A prototype is fabricated and the simulated results are verified through experiments. The attenuator works from DC to 10 GHz with a tunable range of almost 25 dB, the value of reflection attained at maximum attenuation is around -3 dB. © 2017 IEEE.