Silicon (Si) photonics is one of the most promising technologies in many application fields thanks to the mature Si industry, the large Si wafer size and the optical properties of Si and related materials. One of the biggest challenges is the integration of high-performance light sources on Si and much work has recently been devoted to the integration of III-V semiconductor lasers [1]. Their monolithic integration, i.e. direct integration via epitaxy, would open the way to low-cost, large-scale and ultra-dense Si photonic chips [2]. However, only discrete III-V-on-Si lasers have been reported so far [3]. In this work, we demonstrate the monolithic integration of mid-infrared GaSb diode lasers (DLs) on a Si photonic integrated circuit (PIC) equipped with SiN waveguides (WGs) and we demonstrate light coupling into the WGs.