Polyethylene (PE) is widely used in packaging applications today due to its low cost, good processability, and superior toughness. Coextruded blown films are commonly used in PE-based frozen food packaging, with linear low density polyethylene (LLDPE) making up more than 80% of the structure. In recent years, there has been a strong desire to down-gauge the film while maintaining the incumbent packaging toughness performance. Therefore, a LLDPE resin with better toughness performance at cold temperature (< 0 °C) is needed to satisfy the market need. Much research has been done to establish the relationship between the molecular architecture of PE and the dart impact resistance (related to the toughness) at room temperature, but the knowledge at cold temperature is still very limited. Based on our study, high dart impact resistance of LLDPE film at room temperature does not guarantee high dart impact at cold temperatures. Therefore, more knowledge is needed about the cold temperature toughness of LLDPE. In this paper, we provide a fundamental understanding of the influence the basic molecular architecture (e.g. melt index, molecular weight distribution, glass transition temperature) of LLDPE resin has on the dart impact resistance at cold temperature. Dart impact resistance is measured on LLDPE blown films using an Instrumented Dart Impact instrument in a temperature controlled chamber. The results provide guidance for film converters to select LLDPE products to meet the toughness performance needs of PE-based frozen food packaging.