Background: Teeth are among the most important parts of our body which help in mastication, phonetic and esthetic. Now a days tooth extraction can be avoided due to availabilities of most advanced treatment. Mostly, extraction is the treatment of choice for extensive caries and severe periodontitis because of late reporting to dentist due to lack of knowledge. Knowledge about post extraction complications and their management can prevent the occurrence of untoward sequalae following extraction. Previous studies have shown that preoperative patient education can help in decreasing postoperative anxiety, pain and complications. Methodology: This is a questionnaire based cross-sectional descriptive study. The study was conducted during the period of January to March 2018. Total of 250 patients (138 males and 112 females) were included in the study by the convenient method of sampling that visited the dental clinics of college of Dentistry, Taibah University. Validated questionnaire was asked about post extraction preventive knowledge. Categories of answer was good, average and poor according to number of correct answers. The statistical analysis was performed by the Statistical Package for Social Science version 21 (SPSS Inc Chicago, IL, USA). The significant value was obtained by using Chi Square test and p < 0.05 was set to be significant. Results: Females and 31-45 years age group had better post extraction preventive knowledge and there was significant relation. Nationality and education level had no significant relation with level of post extraction preventive knowledge. The patients who had better knowledge followed the instructions precisely. Conclusion: It was concluded that female, patients above middle age group and more qualified patients had more post extraction preventive knowledge and they also followed the instructions very strictly. The importance of study came out that dentist or dental assistant should explain and convince them to follow proper post-operative instruction to avoid complications.