Introduction Grenz ray therapy ( has long been used as treatment for inflammatory skindiaseases R ecent h ealth technology assessment reports have concluded that because ofinsufficient evidence of its efficacy they do not promote further use of GRT for benigndisorders. Aim T o investigate the effect, estimate remission times and summarize the outcome of the GRTseries administered over a six year period for the treatment of inflammatory diseases at theUniversity Hospital Örebro Methods A total of 204 treatment serie s were included by review of patient files spanningfrom 201 5 to 2020. Symptom scores of one to fifteen were recorded at start and end oftreatment. Data on recurrence was collected over a follow up period of 12 months after theend of treatment. Results Al l diagnoses had reduced symptom severity score s post treatment, with psoriasis ofthe scalp showing a 71.4% reduction and genital lichen showing a symptom score reductionof 25.0% Non reponse was lowest for hand dermatitis, and highest for lichen and eczema ofthe body. In patients with an initial effect post t reatment, a majority did not experience arecurrence within 12 months. Conclusion Positive effects were of GRT was indicated especially for scalp psoriasis andhand dermatitis, a ltough effect size is undetermined. The least effect was indicated for genitallichen. Hand dermatitis had the lowest recurrence rate in the follow up period. Furtherresearch of the subject is needed to determine the utility o f the method