ObjectiveTo test the efficacy and possible side effects of a single 20 mg dose of methotrexate injected at the time of laparoscopy, in the treatment of tubal ectopic pregnancy.DesignThe study was a non‐randomised non‐blinded prospective clinical trial.SettingThe study was carried out at two tertiary referral hospitals.PatientsEighteen patients with unruptured tubal ectopic pregnancies and in a stable haemodynamic condition were offered entry into the study and all of these agreed.InterventionsAt diagnostic laparoscopy, 20 mg of methotrexate in 0.8 mL was injected by fine needle in or around the ectopic gestation.Main outcomePatients were followed up as outpatients by serial blood tests until resolution of the ectopic pregnancy was demonstrated by a return of the level of β‐human chorionic gonadotrophin to the normal range.ResultsThere was one failure of treatment. The ectopic pregnancy resolved in the remaining 17 patients. There were no side effects attributable to methotrexate and tubal patency was demonstrated in the eight patients tested by hysterosalpingography.