An insulin pump is the most faithful way of imitating the natural treatment of insulin secretion, the greatest therapeutic reach in the treatment of type 1 diabetes. There are clearly defined indications for the introduction of an insulin pump in therapy, and in addition, good education, cooperation and motivation of the patient are crucial. Aim and objectives of the research: Objectives: 1. To determine whether there are differences in daily activities that contribute to the quality of life of people who are treated with an insulin pump compared to people who are treated with multiple daily insulin injections. 2. To investigate the claim that HbA1c is better regulated in people who are treated with an insulin pump compared to those who are treated with injections. Considering the objectives of the research, the following hypotheses were formulated: H1: There is a difference in daily activities that contribute to the quality of life of people who are treated with an insulin pump compared to people who are treated with multiple daily insulin injections. Hypothesis 1 is divided into 4 sub-hypotheses: H 1.1: There are differences in physical health (DOM 1) that contribute to the quality of life of people treated with an insulin pump compared to people treated with injections. H 1.2: There are differences in mental health (DOM 2) that contribute to the quality of life of people treated with an insulin pump compared to people treated with injections. H 1.3: There are differences in social relations (DOM 3) that contribute to the quality of life of people who are treated with an insulin pump compared to people who are treated with injections. H 1.4: There are differences in the environment (DOM 4) that contribute to the quality of life of people who are treated with an insulin pump compared to people who are treated with injections. H2: HbA1c is better regulated in people treated with an insulin pump compared to people treated with injections. Research methods and data collection techniques: 50 people who are treated with an insulin pump and 50 people who are treated with multiple daily insulin injections, registered and treated in different polyclinics and hospitals in the Republic of Croatia, were examined using an anonymous questionnaire. Respondents filled out an anonymous questionnaire via the Facebook group "Young people with diabetes in the Republic of Croatia". The first part of the anonymous questionnaire consists of sociodemographic data, the second part consists of advantages and disadvantages of treatment, and the third part consists of the WHOQOL-Bref questionnaire - a shortened version of the World Health Organization's quality of life questionnaire. The data were statistically processed in the SPSS program. Results: We assessed the quality of life using a questionnaire with 26 items that form 4 domains. We tested the reliability of the measurement scales by calculating Cronbach Alpha coefficients. Based on the Cronbach Alpha coefficients ( > 0.7), we concluded that the applied measurement scales have a satisfactory level of reliability, which means, they are confirmed as valid instruments for measuring the opinions and attitudes of respondents. Also, based on the obtained Pearson correlation coefficients (p < 0.05 and p < 0.001), we found a statistically significant correlation between the last value of HbA1c and 4 domains. Pearson's correlation coefficient r = -0.133 shows a small negative association between therapy and the last value of HbA1c. Conclusion: To test the first hypothesis, we used the Mann Whitney U test and for all 4 domains we obtained the result that p > 0.05 and concluded that the data do not provide statistically significant data on the difference between the therapy (insulin pen injections, insulin pump) and the 4 domains (physical health, mental health, social relations and environment) which means that the hypothesis is rejected. To test the second hypothesis, the Chi-square test of independence was used, which did not show a statistically significant difference between the used therapies and the last value of HbA1c (χ2(3,n=100) = 3.488; p>0.05; p=0.322), which means that the second hypothesis is also rejected.