The usual practice in using a control chart to monitor a profile is to take samples from the process with fixed sampling intervals. This article considered the use of generalized likelihood ratio (GLR) chart with a variable sampling interval (VSI) to monitor simple linear profiles. The performance of the VSI GLR chart was compared with that of the GLR chart with a fixed sampling rate. The results indicated the superiority of the VSI GLR chart over all possible single step changes in the intercept, slope, and standard deviation. Also, an example was provided to explain the implementation of the VSI GLR chart.