In this study, low‐density polyethylene (LDPE) crystalline structures produced via a solution‐crystallization method on carbon nano‐fillers were characterized. The nano‐fillers used in this study are carbon nanotubes (CNTs) and carbon nanofibers (CNFs). CNTs and CNFs were used to act as a nucleating surface for polymer crystallization. In the case of CNTs, we obtained nanohybrid shish‐kebab architecture by epitaxial crystallization. This is a unique way to bond polymer with nanofillers, in which the CNTs act as shish, while polymer act as kebabs. A pressure‐induced crystallization approach was employed to investigate the effects of crystallization time and pressure on the CNFs/LDPE nanohybrid structure and percent crystallinity. The morphology of the nanohybrids was characterized by scanning electron microscopy (SEM), while differential scanning calorimetry (DSC) was used to quantify the amount of crystalline polymer. The LDPE crystals grown on CNTs had significant morphological differences from those grown on CNFs. The polymer crystals were found to periodically decorate the CNTs with a nanohybrid shish‐kebab (NHSK) architecture, in which CNTs acts as a shish, while LDPE crystals were arranged as circular disks on the CNTs. POLYM. COMPOS., 39:192–200, 2018. © 2016 Society of Plastics Engineers