Abstract: Introduction: The non-surgical periodontal therapy consists of ultrasonic scaling and full mouth disinfection. Ultra sonic scaling is conventionally done in weekly sessions, performed quadrant wise. The Full Mouth Disinfection approach aims to prevent re-infection of already treated periodontal sites by pathogens that reside on other sites and thus improve the effectiveness of non-surgical periodontal treatment. Anxiety, fear and pain experience represent significant problems in the dental practice and are significant factors that discourage the demand for treatment. Thus it interferes in the management of patients during dental treatment. Aim: To evaluate the clinical effects of two different forms of non-surgical periodontal therapy, ultrasonic scaling versus one-stage full-mouth disinfection to the patient based on questionnaire such as Dental Fear Survey, Dental Anxiety Scale and Visual Analogue Scale Materials And Methods: Dental Fear Survey and Dental Anxiety Scale questionnaires and Visual Analogue Scale were applied to 30 patients randomized into two groups. Group I consists of 15 patients who underwent ultrasonic scaling; Group II consists of 15 patients who underwent one stage full mouth disinfection. Periodontal clinical parameters were monitored at baseline and after 4 weeks of treatment. Results: All the clinical parameters are found to be statistically significant results in the FMD group. There was no significant differences between treatment groups with respect to gender, age, income and socioeconomic status. Conclusion: It is concluded that FMD group showed better improvements in clinical parameters when compared to ultrasonic scaling group, but didn’t show any difference with respect to fear, anxiety and pain experiences.