There is growing evidence on the impact of technology addiction on different aspects of college / university students´ life; however, its relationship towards academic achievement has been understudied so far. Following a prolonged period of pandemic restrictions and online study, there is a need to explore how academic achievement was impacted and mediated by different health-related and psychological factors. The aim of this intercultural study was to find out how smartphone / internet addiction, mental health (depression, anxiety, stress, and resilience), and personality traits interact to affect individual aspects of academic achievement of Czech and Chinese college / university students. Data from an online survey that included a number of tests were analyzed using a path analysis. Academic achievement correlated positively with technology addiction in Chinese students, compared to the opposite trend in the Czech sample. Except for the common influences of gender, extroversion, conscientiousness, and stress, there were factors specific to the Chinese sample (agreeableness, anxiety), as well as for Czech students (resilience). Also, the level of explained variance in internet addiction and academic achievement differed in both samples. Future studies may better explore and explain the potentially positive role of technology addiction that is probably specific for many Chinese students in tertiary education.