Both radiotherapy and laser surgery give excellent results in the treatment of T(1a) glottic carcinoma. In this study, we compared the outcome of these treatment options. Demographic details and continuous follow-up with exact cause of death have been recorded prospectively for 351 patients with T(1a) glottic carcinoma at a tertiary referral centre in two consecutive decennia 1986-2005. Patients were treated with radiotherapy (163 patients) until 1996 when laser surgery was adopted as primary treatment (188 patients). The minimum follow-up time was 29 months. Neither the estimated 5-year disease-free survival, the disease-specific survival nor the crude survival differ between the two treatment options. The incidence of mainly local recurrences was equal during the first 3 years, followed by an increase in number of recurrences in the laser-operated patients. The odds ratio for a laryngectomy was 13.5 in patients treated with radiotherapy (P = 0.002), but mortality due to recurrence did not differ between the groups. The incidence of second primaries was equal (11%) but death due to second primaries differed significantly, favouring laser-treated patients (P = 0.003). In conclusion, the relative risk for a laryngectomy when a tumour recurs is 12.7 times higher in patients primarily treated with irradiation for T(1a) laryngeal carcinoma, compared with patients treated with laser surgery. Regarding the treatment costs, treatment impact on patients and organ preservation, we consider laser therapy to be the better treatment option for patients with T(1a) glottic cancer as no difference in survival could be observed.