BACKGROUND: No cure for psoriasis exists for the 1-3% of the American population who suffer from it; however, anecdotal reports from patients with psoriasis visiting Hawaii who purchased kukui nut oil, claim it helped reduce the severity of their lesions. OBJECTIVE: This pilot study was a double-blind, placebo-controlled clinical trial to determine the effectiveness of kukui nut oil as a topical treatment for psoriasis. METHODS: Thirty adult subjects (18-78 year) were recruited from the community for a 12-week randomized, double-blind, placebo-controlled pilot study. Subjects were previously diagnosed with mild, stable plaque psoriasis (less than 15% of total body surface area [TBSA]) and agreed to abstain from other treatments during the course of the study. Following a 4-week washout period the subjects were randomized into a treatment group (15 subjects applying kukui nut oil) or a control group (15 applying the mineral oil placebo). Patients were seen every 2 weeks (seven visits at 0, 2, 4, 6, 8, 10, and 12 weeks) by a dermatological nurse practitioner under the general supervision of a board certified dermatologist. Measurable outcomes included evaluation of one targeted lesion and of the overall severity of their psoriasis using clinical evaluation, Psoriasis Area and Sensitivity Index (PASI), Global Severity of Psoriasis Scale, and photographs. Each patient also evaluated their own lesions daily using the Global Severity of Psoriasis Scale, and noted any side-effects or other treatments used. RESULTS: Although both groups improved, we found no significant difference between the treatment (kukui nut oil) and the placebo (mineral oil) among the 24 out of 30 subjects (80%) who completed the study. No side-effects or adverse events were reported. CONCLUSION: Kukui nut oil did not significantly reduce symptoms of psoriasis; however, this was a small pilot study, and the use of this oil cannot be dismissed without using a larger study population of patients with psoriasis.