This paper investigates the applied uncertainty and sensitivity analysis to resistors used in voltage series operational amplifier circuit. Two resistors bands are considered which are the gold band (5% uncertainty) and the silver band (10% uncertainty). To generate resistors uncertainty sample points, the SIMLAB uncertainty and sensitivity tool is used. A total of sample points based on Sobol’ technique has been created for each resistor band. The voltage series amplifier is modelled in MATLAB/Simulink. A MATLAB script has been written to execute Monte-Carlo simulations for reading the resistor sample points, updating and executing the voltage series model and finally calculating the voltage gain. The result of uncertainty analysis shows that the produced voltage gain is uncertain within the range of for the gold band and for the silver band with respect to a reference voltage gain. The result of sensitivity analysis shows that each resistor, although their values are different, contributes equally contribution to the uncertainty of voltage gain.