There is a wealth of studies which suggest that manager's positive perceptions/expectations can considerably influence organisational performance; unfortunately, little empirical evidence has been obtained from development studies. This first time research explores how Japanese aid workers' perceptions towards the local staff affects their behaviour and performance in cross-cultural project settings. Moreover, this research focuses on the perceptual and behavioural trait differences of successful and unsuccessful aid workers. With cooperation from Japan International Cooperation Agency (JICA), 244 valid responses were obtained from the aid workers (managers) through a webbased survey. As a result of statistical analysis, positive causal relationships were confirmed between perception related factors and behaviour related factors and the organisational performance variable. These results strongly suggest that aid worker¿s positive perceptions result in positive behaviour in local colleagues and subsequently higher organisational performance. In addition, it was discovered that the aid workers' positive perception/expectation about work and their local colleagues was related to higher organisational performance, whilst conversely, the negative perception on their part was generally associated with negative behaviour and lower organisational performance.Although the differences in perceptual tendencies suggested by that these findings apply to Japanese aid managers; however, as human nature is universal, positive perception and behaviour should bring out positive output in most organisations. It is recommended that there is a need for people-related and cross-cultural management skills to ensure successful future activities, and stress management competencies to maintain positive managerial perception on the part of aid workers.