To evaluate patient's subjective preferences to scaling with narrow probe-shaped EMS Perio Slim PS tips compared to conventional tip based on pain perception using the Visual Analogue Scale (VAS). Ten patients were treated using a piezoelectric ultrasonic device (EMS) and two different scaler tips representing a conventional scaler tip and a Perio Slim PS scaler tip in a split-mouth design. Pain was evaluated after 2 minutes scaling using Visual Analogue Scale (VAS). Data obtained was analysed by SPSS version 19.0 using Wilcoxon test. Pain assessment after treatment confirmed by the Visual Analogue Scale (VAS) showed that the Perio Slim PS scaler tip (maximum pain score: 4, minimum: 2) caused less pain than the conventional scaler tip (maximum: 8, minimum: 3) (p-value = 0.007). Using Perio Slim PS scaler tip caused less pain and discomfort during scaling treatment when compared with conventional scaler tip. www.adum.edu.my