Managing diabetes is complicated for many children. It often requires support from an adult during the school day. In Denmark, most children spend 30–35 h a week at school. Nevertheless, diabetes management in schools remains largely uninvestigated. This study aimed to examine the characteristics and organization of diabetes management in Danish primary schools from the personnel’s perspective. All primary schools in Denmark were invited to participate in the study (n = 2129), and 525 schools were included. A questionnaire was constructed and sent by email. Questionnaire data are presented in the descriptive statistics and compared with the ISPAD guidelines. According to 77.2% of respondents, school personnel had received training in diabetes management, and 78.5% of the schools had at least one person available for diabetes support every day. Respondents felt prepared to help the students with counting carbohydrates (38.9%), dosing insulin (39.1%), and helping the students during high (52.1%) or low (60.3%) blood sugar levels, insulin chock (35.2%), or during activities (36.3%). Yet, diabetes management was a challenging task. Only 61.7% had an action plan for diabetes management, 37.4% had face-to-face information meetings with the parents, and 55.1% of respondents reported having sufficient time to cooperate with the parents.