This study investigates the relationships between firm characteristics (region, firm size, firm age, and product category) and Industry 4.0 technology adoption in the Vietnamese apparel manufacturing industry. As the key Industry 4.0 technologies, Artificial Intelligence (AI), Interactive Robotics, Smart Sensors, Big Data, 3D Printing, physical Cyber-Physical Systems (CPS), and human-robot interaction were included to examine technology adoption. The hypotheses were tested using a series of Chi-square analyses with data gathered from 210 Vietnamese apparel-manufacturing firms. The results indicate no clear pattern of associations between firm characteristics and technology adoption and provide empirical support for firms' strategic adoption of a certain set of Industry 4.0 technologies in line with their firm characteristics. On the other hand, the findings from scatter charts indicated that AI, Interactive Robotics, and 3D Printing are three key technologies that apparel firms applied the most and at a similar level.