— This paper presents a tentacle-based obstacle avoidance scheme for omnidirectional mobile robots that must satisfy visibility constraints during navigation. The navigation task consists of driving the robot towards a visual target in the presence of environment (static or moving) obstacles. The target is acquired by an on-board camera, while the obstacles surrounding the robot are sensed by laser range scanners. To perform such task, the robot must avoid the obstacles while maintaining the target in its field of view. The approach is validated in both simulated and real experiments.