To develop more effective intervention strategies against dengue, it is necessary to identify determinants of knowledge, attitudes, and practices (KAP), which may be influenced by the dengue experiences of the population at risk. The aim of this study was to assess and compare KAP regarding dengue prevention between Thai primary school children with and without experiences of dengue. A cross-sectional study was conducted among children between ages 8 and 13, attending the 50 public primary schools in Kanchanadit district, between October and November 2019. A 32-item questionnaire was used to collect children's socio-demographic characteristics (4 items), health information (2 items), knowledge (10 items), attitudes (7 items), and practices (9 items) towards dengue prevention, which required 30 min to complete. The KAP between groups was then statistically compared, to identify possible causes of observed differences. Of 1979 children, 15.6% self-reported that they had been infected with dengue, while 84.4% had no history of the disease. Most children indicated that they obtained dengue-related information from primary school teachers (73.6%) and their parents (68.5%). No statistically significant differences in mean KAP scores were observed between children with and without dengue experiences ( P > 0.05). When KAP scores were categorized as good or poor levels, based on an 80% cut-off, 12.3% of all children had good dengue-related knowledge, 41.6% had good attitudes, and 25.9% reported good preventive practices. Dengue experience was significantly and positively associated with exercising good preventive practices (odds ratio [OR] = 1.34, 95% confidence interval [CI]: 1.03–1.75, P = 0.031). There were significant positive correlations between attitudes and practices in both children with and without dengue experiences ( P < 0.001). To enhance KAP towards dengue prevention, further efforts are needed to increase routine dengue health education programs for primary school students who have and have not experienced dengue, and to improve health education programs within communities, especially to assist guardians with the dissemination of dengue literature.