Pointing and dragging are fundamental actions by input devices when interacting with computer graphical user interfaces (GUIs). Cockpits on modern vehicles have been increasingly equipped with GUIs, enabling pointing and dragging tasks to be frequently performed under vibration conditions. However, factors influencing these fundamental actions under vibration conditions have not been fully explored. This study aimed to explore the effects of vibration, input devices, and target size on the performance and perceived workload in basic human–computer interaction tasks. Twenty‐seven participants completed an experiment where they were required to conduct two pointing tasks and one dragging‐and‐dropping task using four input devices (mouse, touchscreen, trackball, and remote hand‐controller) under static and three vibration conditions (lateral, fore‐and‐aft, and omnidirectional vibration) with two target sizes (small and large). The results indicated that vibration caused longer task completion time, higher error rates, and more workload in completing pointing and dragging tasks. Both target size and input device affected task performance in vibration environments. Highest workload was perceived when using remote hand‐controller, followed by trackballs under all vibration conditions; there was no significant difference between mouse and touchscreen, except in terms of physical demand. The findings suggest that practitioners should fully consider the joint effects of input device, target size, and vibration to counteract adverse influence of vibration and optimize user interface designs of human‐computer systems in vibration environments.