Diabetes mellitus (DM) is a chronic disease that has become a global health problem. As the population of people with diabetes is growing worldwide, the prevalence of complications associated with DM, such as diabetic foot, also increases. Neuropathy and high plantar pressure are the two most frequent causes of foot ulceration. Since diabetic wounds tend to heal slowly, it is crucial to prevent diabetic foot ulcers before they occur. In this study, the efficacy of a sock developed for diabetes in the previous research of the authors was investigated in a clinical study with the participation of patients with diabetes over a 6-month period. At the end of the study, it was observed that none of the participants had experienced any new ulcers, bacterial or fungal infections, or callus formation during this research. Moreover, a slight decrease in pressure was observed for the first, second, and third metatarsal bones when the socks were worn on day 1. On the other hand, pressure reduction was identified for the fourth and fifth metatarsal bones in all following measurements. However, analyses revealed that duration of usage did not have a statistically significant effect on overall plantar pressure. It was also found that pressure on the fourth and fifth metatarsal bones significantly decreased. Assessment of wearing comfort revealed the satisfaction of the patients, as well. Based on the promising outcomes of this clinical evaluation, these socks developed for people with diabetes can be strongly expected to help avoid diabetic foot ulcers.