Type 1 diabetes mellitus (DM1) is the most common form of diabetes in children. A key role in DM1 control is the balance between insulin administration, diet and physical activity. People with diabetes very often change their diet in order to achieve the best possible short-term and long-term control. One of the ways to change the diet is a low-carbohydrate diet (LCD), which includes the intake of less than 130 grams of carbohydrates per day, or less than 26% of the total daily energy intake. The paper presents the results of research on the use of LCD in children with DM1 treated at the Department of Pediatric Endocrinology and Diabetes, University Hospital Center Zagreb. Out of 137 respondents, 80% are familiar with LCD. The most common source of information about this form of nutrition is social networks and the Internet (33%). In the examined group, 33% of respondents used LCD, most often for the purpose of achieving a better blood glucose concentration. Better glycemic values with LCD were reported by 70% of participants, 49% reduced insulin requirements, and 56% improved glycosylated hemoglobin values during this period. The majority of children participated in LCD for less than a year. The main reason for discontinuation was difficulties in adherence. The majority of participants who implemented LCD (93%) consider this diet useful and plan to use it again. Data on the effect of LCD in children and adolescents are scarce. Therefore, further research is needed in order to examine the influence of LCD on the growth and development of children, determine the potential negative consequences on bone mass, the cardiovascular system, kidney and liver function, but also examine the potential beneficial effects on better metabolic control, less glycemic oscillations and less insulin requirements. Our results stress the importance of discussing the use of LCD in patients with DM1 and providing patients with scientifically based information and education.