Introduction. Ectopic pregnancy is one of the major emergencies in obstetrics and gynecology, being associated with a high rate of intra-abdominal bleeding if it is not diagnosed in a timely manner and is not subject to proper management. Aim of the study. To determine the effectiveness of Methotrexate in the treatment of ectopic pregnancy and which are the ß-HCG values to which it has the highest sensitivity. Materials and methods. A retrospective study was conducted during 2016-2019, in which we found out 320 cases, of which 45 cases were treated with Methotrexate solution - a single dose. Inclusion criteria was : ß-HCG ≤ 5000 mIU / mL in tubal pregnancy with gestational sac diameter ≤ 4 cm, lack of cardiac activity and no free fluid in Douglas space; Patients with ßHCG ≥ 5000 mIU / mL and gestational sac diameter ≥ 4cm and presence of cardiac activity were excluded. Results. The success rate from a single dose of Methotrexate represented u = 10 cases - 22.8%, compared with failure u = 35 cases - 77.8%, which required surgery. The average age of the patients was 30 years, including the patients between 18-42 years. The success rate decreased with the older age of the patient. Pregnancies with more frequent occurrence at primiparity 7 cases - 70% and multiparity 3 cases - 30%. The average term of pregnancy at the time of diagnosis 4.3 weeks, p = 0.472. The success rate decreased with the increase of the gestation term. The diameter of the gestational sac was 2.3-4cm, and the success rate decreased in patients with gestational sac greater than 4cm, p = 0.132. The highest success rate was found in patients with a gestational sac of 2-3 cm in diameter - 67.2%. The study showed us a significant difference in the location of the pregnancy, although 56% were pregnancies located on the right (u = 26 patients) and 44% were located on the left (u = 29 patients). The β-HCG value ranged from 329-5200 mIU / mL, with an average of 1234 mIU / mL. Surgery against ineffectiveness required 35 cases (77.85%) that resulted in increased ß-HCG or tubal rupture and abdominal pain. All cases u = 35 (77.8%) resulted in surgical laparoscopy. In u = 7 cases, were detected tubal miscarriages performing salpingoplasty as treatment in 20% of cases and in 80% of cases was performed laparoscopic tubectomy. Conclusions. Our study demonstrated a low rate of efficacy of the conservative method of treatment of tubal pregnancy in evolution by administering Methotrexate. The data comes to contradict the beneficial experience and the weight of the success cases offered by the specialized literature in the conduct of patients with this pathology. If we strictly adhered to the inclusion criteria and the protocol of administration, it would be interesting to carry out an evaluation of the pharmacokinetics of the indigenous Methotrexate production preparation.