Vibro-tactile displays convey messages by presenting vibration to the user's skin. In recent years, the interest in and application of vibro-tactile displays is growing. Vibratory displays are introduced in mobile devices, desktop applications and even in aircraft . Despite the growing interest, guidelines on the design of vibrotactile displays are still lacking. Existing guidelines are mainly concerned with passive displays, such as Braille labels on controls, nibs on keyboards and notches on smart cards [2, 3, 4]. In this paper we focus on active displays, either consisting of a single vibrating element (used in for example mobile phones and computer mice) or numerous elements (used in for example active Braille displays and body suits [5, 6]). This paper discusses a first set of guidelines, dealing with the basic vibro-tactile parameters. The set is mainly derived from neurophysiological arul psychophysical data. The guidelines indicate the relevant parameters as well as possible pitfalls. As such they can serve as a point of departure for interface designers. Important expansions of the set can come from user evaluation studies and examples of best practices.