Ground state properties of intermetallic YCo9Si4 are investigated by means of temperature-dependent electrical resistivity measurements under pressure using both a diamond-anvil cell and a piston-cylinder cell. At ambient pressure, YCo9Si4 shows weak itinerant ferromagnetism below 25K with an ordered moment of about 1.6μB/f.u. The temperature-dependent electrical resistivity exhibits below 10K a power-law behavior R(T)=R0+ATn. The exponent n changes from n≃1.7 at ambient pressure to about 1.5 at 6GPa, referring to non-Fermi liquid behavior. The characteristic temperature decreases with pressure, implying a decrease of the ferromagnetic transition with pressure as well. The initial decrease of the ordering temperature is dTC/dp≃-2K/GPa. Both, the pressure-dependent evolution of TC as well as of the coefficients A and n indicate that a ferromagnetic quantum critical point will be reached under pressure of the order of 6GPa.