Halloysite nanotubes (HNTs) have been used as a new type of filler for acrylonitrile–butadiene rubber (NBR) matrix. The NBR/HNT nanocomposites were prepared using a two-roll mill by adding 0–7 parts per hundred rubber (phr) HNTs, and the effect of the loading of HNTs on the curing behavior, mechanical, and microstructural properties were also investigated in this study. The cure characteristics showed that the cure time (t₉₀) and scorch time (t_s2) decreased, whereas the maximum torque (M_H) exhibited an increasing trend from 0 to 7 phr. The tensile properties improved until optimum loading of HNTs (5 phr) and thermal stability increased with increasing HNT loading. The morphological study revealed the HNTs homogeneously dispersed inside the NBR matrix and good interaction occurred between HNTs and NBR.