The advancement of mobile technology has enabled people's easy access to the Internet and enjoying real-time communication with multiple parties via social media. Smartphone use seems ubiquitous, but research has found that excessive and dysregulated smartphone use may have drawbacks, leading to mobile phone problematic use (MPPU) and negative consequences, including symptoms of dependence, social isolation, behavioural and affective problems [1], [2] and poor academic pursuits [3]. The current study aims to understand the relationship between MPPU, executive functions, and psychological health among college students. College students (N=233) were recruited, including 198 Hong Kong participants and 35 United Kingdom participants, with 56 male, 174 female and 3 failed to indicate their gender, mean age of 21.63 (SD=4.97). Participants were recruited to complete a set of psychometric scales, namely Mobile Phone Problematic Use Scale, Behaviour Rating Inventory of Executive Function, Beck Depression Inventory, and General Health Questionnaire, to measure MPPU, executive function, depression, and mental health respectively. The findings showed significant correlation between variables and that participants who responded higher in MPPU scored lower in all nine subscales of executive functions. High scores in MPPU was also associated with higher level of depression, mental health problems. Multiple regression found that depression significantly predicted problematic smartphone use. In Cross-cultural comparisons, Hong Kong participants reported using more expensive smartphones than the United Kingdom counterparts. Hong Kong participants who were high in MPPU tended to use more expensive smartphones. The current findings contributed to previous research on MPPU, interference in academic performance and negative influence on psychological well-being. As smartphone use is becoming more prevalent, further research on the intervention of MPPU is needed among college students to be able to enhance their executive function and improve psychological health.