Diabetes mellitus is a highly prevalent chronic health condition that places patients at greater risk for psychological problems. Yet, there is still a lack of empirical evidence to support the use of psychological interventions in patients with diabetes. In this trial, we examined the feasibility of a novel intervention: individual mindfulness-based cognitive therapy (I-MBCT), an adaptation of the well-known group MBCT. We examined the feasibility of screening, recruiting, randomizing, and retaining patients into the study and their acceptability of I-MBCT. Descriptive analyses were performed to explore changes in patients' functioning over time, comparing those receiving I-MBCT with those in the waitlist control group. A sample of consecutive patients with diabetes was screened on psychological symptoms and when reporting elevated levels of symptoms, approached for the intervention trial. Patients completed self-report questionnaires pre- and postintervention regarding psychological functioning (i.e., depressive symptoms, diabetes-related distress), mindfulness (i.e., act with awareness, accept without judgment), and attention regulation. In total, 499 patients were approached, of whom 347 patients filled out the screening questionnaire. Of these, 38 patients were eligible, and 24 were randomized in I-MBCT (n = 12) or waitlist (n = 12). Two of the 12 patients assigned to I-MBCT dropped out of the intervention. Most patients were very satisfied with I-MBCT. Preliminary analyses suggest that, compared to controls, patients receiving I-MBCT reported significant reductions in depressive symptoms and diabetes-related distress and improvements in act with awareness and attention regulation. This is the first RCT on individual-based MBCT, providing encouraging evidence for its feasibility and acceptability. Preliminary findings also suggest that I-MBCT may be associated with improvements in psychological functioning, which support larger trials on this alternative form of mindfulness-based therapy.