Aim: To determine closest speaking space in different Angle’s malocclusion classes. Study design: Descriptive Cross Sectional. Place and Duration of Study: .Department of Prosthodontics, Liaquat University of medical and Health Sciences Hospital during period of July 2021 - Dec 2021. Methodology:Total  111  Patients  from  both  genders  with  age  range  18-45  with  intact  1st  and  2nd premolars were alginate impressions were taken. Polysiloxane Elastomeric impression material bites in 1.5cm thickness were placed bilaterally on occlusal surfaces of mandibular premolars and molar teeth in patients oral cavity. Patients were instructed to swallow and repeat the Sindhi Language word “SASSI”. The elastomeric material bite blocks were removed and thickeness was noted down for each patient at premolar region using digital vernier calliper. The measurements were recorded in millimetres. Results: A total of 111 patients were examined, with an average age of 35 years and a range of 18 to 45 years (Table 1). Males made up 56 % of the population, while females consists of 44 % (Figure 1). According to occlusion, the majority of patients had class I 50 (45 %), class III 29 (26.1 %), and class II div I and II 16 (14.4 %) correspondingly (Table 2). According to the mean closest speaking space, it was highest in class II div II 7.05+2.38 mm and  in class II div I 4.81+3.47 mm, with 2.02+0.75 mm in class I and 1.20+1.08 mm in class III (Table 3). Conclusion: It was concluded that closest speaking space was significantly increased in angles class II patients whereas decreased in angles class III.