This research presents study of barrier properties of the injection moulded bottles based on high-density polyethylene, polyamide-6 and nanoclay (HDPE/PA-6/NC) nanocomposites. In fact, the effects of compatibilizer type and contents of nanoclay, PA-6, and compatibilizer were assessed using response surface methodology. Investigation of individual effects showed that increase in nanoclay and PA-6 contents leads to improvement of the barrier properties, whereas compatibilizer content had an optimal level. Among three types of compatibilizers, Fusabond had the best performance. The interaction of effects of the nanoclay and PA-6 contents was very considerable. The highest barrier properties are obtained when these parameters were in high and low levels (in the range of study), respectively. Analysis of variance revealed that compatibilizer type was the most significant parameter. Eventually, using MINITAB software, a correlation for predicting the rate of mass reduction in the nanocomposites was developed.