The study aimed at verifying the effectiveness of a training program in the development of the knowledge of kindergarten teachers about ADHD and their skills with children in the governorate of Interior in Oman. The study population included all the teachers in the kindergartens in the governorate of the Interior, and a sample of 30 teachers was selected for the study. The sample was equally divided into two groups. One group of 15 was experimental and the other group of 15 was a control group. After the pretest, the interventional group received a training program. The comparison group did not receive any training. A total of 17 sessions were conducted at the rate of 3 sessions per week for six-weeks. The results showed the following: Significant statistical were found between the means of the two groups (experimental and control) in the post-test the knowledge of kindergartens teachers in ADHD and their skills in dealing with children in favor of the experimental group. Significant differences were found in the pre- and post-tests in the experimental group's average scores in the development of the knowledge of kindergarten teachers in ADHD and their skills in dealing of with children in favor of the post-test. There were no significant differences indicative differences were found in the average scores of the experimental group in the post-test and the follow up tests regarding the knowledge of kindergarten teachers in ADHD and their skills in dealing of with children. The results of the study showed that the training program was effective in developing the skills of kindergarten teachers and in enriching them with procedures and strategies in dealing with children.