Shell and tube heat exchanger (STHX) is a class of indirect contact heat exchangers which has wide applications in various industries. In this paper, the shell-side performance characteristics of a small STHX with differently notched continuous helical baffle (CHB) geometries are numerically studied and compared with same CHB without notched regions. The indentations are uniquely produced by placing the notch near the core of the heat exchanger, thereby conferring the flow with low-pressure drop regions. Two set of models of inner notched continuous helical baffle (ICHB), i.e., ICHB1 and ICHB2, are studied with notch width of about 5% and 10% of the inner shell diameter of the same heat exchanger. In comparison with the CHBSTHX, it is seen that the STHXs incorporated with ICHBs, the heat transfer rate dropped slightly, but a significant decrease in pressure drop is observed. It is found that the heat transfer coefficient to pressure drop ratio for ICBH1 and ICHB2 shows significant increase in comprehensive performance of about 3.5% and 32.42%, respectively, when compared with same CHB without notched regions.