The study is entitled Work Motivations Affecting Self-Efficacy and Work Effectiveness of Flight Attendants of Airlines in Thailand with the objectives to (1) investigate flight attendants' perception of work motivation (2) investigate flight attendants' perception of self-efficacy and (3) investigate work motivation influencing self-efficacy and work effectiveness. The research samples are flight attendants of Thai Airways and Bangkok Airways, randomized via simple random sampling. The data was collected by using questionnaire and then analyzed to assess the characteristic of work motivation for self-efficacy and work effectiveness by using the Mean and Standard Deviation. Pearson's linear statistical correlation analysis was also used to analyze the relationship between work motivation, self-efficacy and work effectiveness. The study findings are as the followings.