This paper deals with the problem of guaranteed cost control for a class of nonlinear networked control systems (NCSs) with time‐varying delay. A guaranteed cost controller design method is proposed to achieve the desired control performance based on the switched T‐S fuzzy model. The switching mechanism is introduced to handle the uncertainties of NCSs. Based on Lyapunov functional approach, some sufficient conditions for the existence of state feedback robust guaranteed cost controller are presented. Simulation results show that the proposed method is effective to guarantee system’s global asymptotic stability and quality of service (QoS).