Twenty-four patients with previously untreated T1 transitional cell carcinoma of the bladder were treated with oral methotrexate 50 mg weekly for 18 months. Thirteen developed tumour recurrences (recurrence index 11 per 100 patient months at risk) and in one-third of the patients treatment was stopped because of unwanted side effects. These results are no better than our previous experience with intravesical Adriamycin, thiotepa or cisplatin.