In this work, a novel approach for the computer-aided noise analysis of a multiwall carbon nanotube (MWCNT) is proposed. A transmission line model of the MWCNT and a noise correlation matrix based on admittance representation are used for the computer-aided noise analysis. This work presents a simple, fast and effective noise analysis approach for the MWCNT. The noise figure is computed for different values of the parameters of the MWCNT for determining the effects of parameter values on the noise figure of the MWCNT. The results of the computer-aided noise analysis of the MWCNT are given and discussed in detail. According to the results, the variation of the distance from the ground plane of the outer shell has little effect on the value of noise figure, when the value of inner radius or the total number of shells increases the value of noise figure decreases. Therefore the noise figure decreases with increasing diameter because the diameter increases with the increasing value of inner radius and the total number of shells. The value of noise figure increases when the value of nanotube length or physical absolute temperature increases. The value of noise figure decreases with the decreasing value of source admittance.