The aim of this cross sectional study was (1) to identify and compare the approaches which are used to care for carious primary molars between pediatric dentists (PDs) and general dental practitioners (GDPs) in Saudi Arabia and (2) to evaluate the knowledge level of the most appropriate treatment decisions for both groups with regard to caries in primary molars and its relation with demographic variables. A random sample of 600 GDPs and all registered PDs (n = 100) in the Saudi dental society in 2016 were emailed a two part questionnaire; the first part included questions about demographic data and the second part investigated knowledge of the participants of the most appropriate treatment decision in four hypothetical case scenarios in which the severity of caries in a single primary first molar differed. Data were analyzed using chi square and ordinal logistic regression statistical tests. The significance was set at 0.05. The average knowledge score was 1.28 for GDPs and 1.80 for PDs. There were significant differences between both groups on their choice of the most appropriate treatment option in three out of four scenarios. Two factors significantly improved the participants? knowledge; age and qualification (P<0.050.05). PDs were more interventionists, ready to perform pulpotomy and extraction in the absence of equally appropriate treatment options. GDPs and PDs in Saudi Arabia had different treatment approaches of different carious conditions affecting primary molars. PDs had moderate but significantly better knowledge of the most appropriate treatment option than GDPs.