Background and Objectives: Primary teeth and the integrity of the primary teeth are very important for the normal growth and progress of the occlusal relationships and the dentofacial structures. Premature loss of the primary teeth may lead to the loss of the arch length needed for the eruption of permanent teeth and thus lead to rotation, crowding, and impaction of permanent teeth. This study aimed to determine the prevalence of premature loss of primary teeth among children aged 6-10 years in Sana'a city, Yemen. Materials and methods: This observational cross-sectional study included 1091 children, aged 6-10 years. An experienced examiner the first author carried out all clinical examinations under natural light. Data were collected including age and missing teeth. Results: The results showed that 26% of the sample suffered premature loss of primary teeth with no significant difference between the sexes (P> 0.05). There was low  in prevalence of premature loss of primary teeth in 10 years (17.7%), while the rate raised to 29.7%, 31.6%, and 31.7% in 6,7 and 9 years respectively. When considering the number of teeth, the prevalence of one premature loss was 10.8%, followed by two premature losses (9.8%), while the loss rate of 3 or more was5.4%. Considering dental arch 61.8% of loss was Mandible loss, while the loss in Maxilla was 38.1% only. The most common missing tooth is the first lower right primary molar (17%). Conclusion: The prevalence of premature loss in our study is similar to that of developing countries, the rate was low at 10 years for children, while the rate increased at 6,7 and 9 years; most of the loss was in the lower jaw and the most common missing tooth was the right lower primary molar. This result determines the importance of increasing awareness of this problem and focusing on the need for more preventive efforts to maintain healthy and natural teeth that improve the chewing function and aesthetic appearance of children and the entire population. Peer Review History: Received 25 July 2020; Revised 15 August; Accepted 26 August, Available online 15 September 2020 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Name: Dr. Mohamed Amin El-Emam Affiliation: Department of Pharmacology and Therapeutics, Faculty of Pharmacy and Drug Manufacturing, Pharos University in Alexandria (PUA), Alexandria, Egypt. E-mail: mohamed.elemam@pua.edu.eg   Name: Dr. Mohammad Tauseef Affiliation: College of Pharmacy, Chicago State University E-mail: mtauseef@csu.edu   Comments of reviewer(s): Similar Articles:  CAUSES FOR EXTRACTION OF PERMANENT TEETH IN GENERAL DENTAL PRACTICES IN YEMEN PREVALENCE AND CAUSES OF TRAUMATIC DENTAL INJURIES TO ANTERIOR TEETH AMONG PRIMARY SCHOOL CHILDREN IN SANA'A CITY, YEMEN PREVALENCE OF MALOCCLUSION AMONG YEMENI CHILDREN OF PRIMARY SCHOOLS RISK FACTORS OF PERIODONTAL DISEASES AMONG YEMENI YOUNG DENTAL PATIENTS