Using the extended task-technology fit (TTF) model, this paper investigates how certain factors (e.g. task characteristics, technology (i.e. intranet) characteristics, middle managers' demographic characteristics, task-technology fit, and perceived usefulness and usage) affect the port middle managers' job performance. Numerous organizations in the port industry constitute the population of interest. The preliminary results suggest that the majority of middle managers believe that intranet could improve their job performance. The results from the structural equation modelling (SEM) indicate that task characteristics and intranet characteristics significantly justify their variance on task-technology fit. However, demographic variables do not predict task-technology fit. Perceived usefulness is found to be a predictor of intranet usage. Task technology fit, on the other hand, significantly predicts usage and explains the variance on middle managers' job performance. This study is the first study to investigate the effects of intranet usage and managerial performances in an integrative perspective, taking into account various user acceptance models and users' demographic characteristics.