Work ability is an important component of occupational health assessments and reflects how a persons' physical and mental health affect their ability to perform their job. However, little is known about factors relating to the work ability status of flight attendants. The aim of this study was to investigate the physical, mental, and work-related factors that affect flight attendants' work ability. A questionnaire-based cross-sectional study and simple random sampling was conducted with participants employed at a Taiwan-based airline for longer than 1 yr. Analysis of variance and Pearson correlation tests were carried out to analyze work ability according to the flight attendants' social demographics, physical and mental health, and work-related factors. Multiple regression analysis was used to predict the flight attendants' work abilities. A total of 472 flight attendants were recruited and the response rate was 78.67%. The work ability of the flight attendants ranged from 'moderate' to 'excellent' (WAI score, 34.1 ± 1.8 to 45.1 ± 1.5). In a regression analysis, work ability was positively associated with gender, age, and good eating habits; in contrast, insomnia and work-related burnout were negatively associated with work ability (R² = 32.4%). Insomnia, work-related burnout, and eating habits had a significant impact on flight attendants' work abilities. Hence, it is important to address insomnia and high workloads and maintain a healthy lifestyle in the workplace.