Rate-equation model with a four-level system is used to study relative intensity noise (RIN) in III-nitrides quantum-dot (QD) lasers. These levels are: the ground- and excited-states in the QD, the wetting layer (WL) and separate confinement heterostructure (SCH) layers. The most possible relaxation paths and carrier transport are considered in two types of QD structures: GaN/AlxGa1-xN/AlN and InxGa1-xN/ In0.04Ga0.96N /GaN. Effect of: QD and WL compositions, QD sizes, doped and undoped active regions is studied. The RIN is shown to be reduced with higher Al content in the WL, while an increased is shown for InGaN QD structures. RIN decreases with size reduction. Increased doping until 12 acceptors/QD reduced RIN also. The article presents some promising patents on Quantum-Dot Lasers.