A player may request that her coach go on-court during a match to provide coaching. On-court coaching is allowed at all women's tournaments, apart from the four grand slams. This type of communication might significantly improve player’s performance on the court. However, no studies to date have focused on non-verbal communication between coaches and players in tennis. Accordingly in the present study we investigated the non-verbal aspect of communication – during on-court coaching - between coaches and players in tennis. Data was collected through 110 on-court coaching videos from 2014, 2015 and 2016 WTA tournaments. We observed 90 seconds of conversation between coach and player on-court and following analysis included six components of non-verbal communication: personal space, hand gesticulation, eye contact, coach-player ratio, touch and player´s listening. More than 70% of coaches are using good signs of non-verbal communications such as open-hands towards the player. On the other hand, 34% of coaches do not use any kind of physical contact (tap, high-five, etc.). Worth mentioning is that 91% of coaches are using eye contact during on-court coaching but 9% of them wear sunglasses and that is not recommended way of communication. Tennis today requires the tennis player to have a very high level of readiness. An effective communication during on-court coaching could be very beneficial tool to improve performance profiles of tennis players. Additional studies are needed to identify communication interventions that can increase performance with the ultimate goal of achieving more successful athletes.