The Taguchi grey relational analysis (GRA) method is firstly employed to investigate the geometric and flow parameters on the comprehensive performance of a heat exchanger tube with perforated disk inserts. The investigated flow and geometric parameters are Reynolds number, pitch ratio, diameter ratio and perforation index, respectively. The experiments are carried out by using Taguchi’s L18 factorial design experiments. The geometric and flow parameters are optimized and the parameters are ranked based on the GRA. The percentage of influence of each factor on the performance of heat exchanger tube is also quantified. An experimental run is conducted using the optimal design condition, which was obtained from the analysis, to validate the improvement in the cumulative performance of such kind of heat exchanger. This study also shows the feasibility of the hybrid Taguchi-GRA technique for predicting performance, optimization and improving the design of these heat exchangers.