The interest in MoS 2 for radio-frequency (RF) application has recently increased1'2. However, little is known on the scaling behavior of transistors made from MoS 2 for RF applications, which is important for establishing performance limits for electronic circuits based on 2D semiconductors on flexible and rigid substrates. Here, we present a systematic study of top-gated trilayer MoS 2 RF transistors with gate lengths scaled down to 70 and 40 nm. In addition, by introducing "edge-contacted" injection of electrons3 in trilayer MoS 2 devices, we decrease the contact resistance and as a result obtain the highest cutoff frequency of 6 GHz before the de-embedding procedure and 25 GHz after the de-embedding procedure.