In Container Terminals, managing the external truck arrivals is one of the essential managerial activities that, typically, the terminal operators conduct continuously on the short term using a Truck Appointment System (TAS). However, the trucking companies are influenced by the developed appointments and schedules which affect their operations and resources. This paper introduces a collaborative TAS to enable the trucking companies and container terminals to share making the decisions on scheduling the external truck appointments. This paper proposes a Dynamic Collaborative Truck Appointment System (DCTAS) which adopts a simulation optimization approach which integrates a discrete event simulation model with a mixed integer programming model. The DCTAS considers some realistic parameters that enhance the development of reliable appointments that fit the dynamic and stochastic circumstances of container terminals environment. The performance of the developed DCTAS is investigated by solving a numerical instance. The results show that both the container terminals and trucking companies can gain benefits from using the DCTAS. Yard efficiency performance indicators such as the maximum queue lengths, average waiting times, maximum waiting times and average truck turn times are improved using the developed appointment system.