Aim. To describe differences in healing time of diabetic foot ulcers for patients treated at the Copenhagen Wound Healing Center, Bispebjerg Hospital, between the years 1999/2000 and 2011/2012. The Center is highly specialized and receives diabetes patients with hard-to-heal foot ulcers. A further aim is to attempt to find predictors of healing time of diabetic foot ulcers. Methods. A retrospective descriptive study of records from patients with diabetic foot ulcer treated at the Copenhagen Wound Healing Center in 1999, 2000, 2011, or 2012. Follow-up data was collected until the 3^rd of August 2018. Results. Median time (range) to healing was 6 (61.3) months in 1999/2000 and 6.6 (67.8) in 2011/2012 (p=0.2). About 33% of ulcers were healed, 17% were minor or major amputated, and 1.5% were dead within one year in 1999/2000, whereas 30% of ulcers were healed (p=0.6), 14% were amputated (p=0.2), and 12.8% were dead within one year in 2011/2012 (p<0.001). The single factor found significantly associated with longer ulcer duration was infection. Related to shorter ulcer duration were toe localization of the ulcer and good glycemic control. Conclusion. The median time to healing of a diabetic foot ulcer was long, around 6 months and with a high recurrence rate in 1999/2000 as well as in 2011/2012. Some factors were found to be significantly related to healing time, and intervention addressing these may improve the time to heal, although such interpretations must be taken with precaution from the present study and should be proven in randomized prospective intervention trials.