Objective: To decide whether partial nail extraction with phenolisation or with partial excision of the matrix should be the standard treatment in patients with ingrowing toenails of the hallux. Design: Randomized clinical trial with 12-month follow-up evaluations performed by observers who did not know which procedure was applied. Setting: Outpatient department of a surgical teaching hospital. Patients: Fifty-eight consecutive patients with a total of 63 ingrowing toenails were randomized. Intervention: Thirty-four partial matrix excisions ("matrix" group) and 29 phenolizations ("phenol" group) were performed. Main Outcome Measures: Recurrence rate, postoperative morbidity (pain, wound exudates, and scar discomfort), and time to complete recovery (wearing shoes, performing normal activities/work). Results: Recurrences were seen after 7 procedures in the matrix group and also after 7 procedures in the phenol group, of which patients were symptomatic and required a second operation in 4 and 3 instances, respectively. None of the observed differences in wound healing, postoperative pain, and recovery were statistically significant. Conclusions: Partial matrix excision and phenolization are equally effective in treating ingrowing toenails. Because the use of the toxic agent phenol should be avoided, partial matrix excision is the preferable procedure. But in view of the high recurrence rate, there is a need for further improvement of the treatment of ingrowing toenails.