Tetanus is a bacterial infection caused by the toxin ofClostridium tetani. While it primarily affects newborns, people with incomplete vaccination schedules, it can also impact people of any age, especially in developing countries. Even though in the last 20 years several initiatives have been implemented worldwide to reduce the impact of this disease, regions like South Asia and sub-Saharan Africa have registered mortality rates highest since 2015-2019. In Latin America, regional immunization coverage rates were reported at 89% in 2017 for diphtheria-tetanus toxoid and pertussis (DTP-3), although Costa Rica has reported decreased coverage rates of the national immunization schedule from 2019 to 2021.In this case study, we present a 53-year-old woman from Puntarenas, Costa Rica diagnosed with progressive systemic tetanus who developed status epilepticus. She previously was assessed in a central hospital of Costa Rica for paresthesia in her right upper limb of three months of duration, myoclonus and difficulty walking in the last weeks; the presumed diagnosis was Guillain-Barré syndrome. During her hospitalization she had three generalized tonic-clonic seizures treated with diazepam and phenytoin.Since there was no improvement, she was transferred to our medium-sized private hospital for the treatment of painful spasms and weakness in the lower limbs. On initial evaluation, no injury was found. She was initially treated with midazolam and magnesium sulfate for presenting seizures-like spasms in the lower limbs and then generalized without loss of consciousness for up to 15 minutes, mainly associated with desaturation, tachycardia and tachypnea. In the differential diagnosis, muscle contractions linked to hypocalcemia, neurosyphilis and epilepsy were ruled out. Despite this, magnetic resonance imaging showed fractures in T11, L1 and L2. Mainly due to the presence of spasms, opisthotonos and history of seizures and a wound on the hand four months ago, she was diagnosed with tetanus.Among the initial management, tetanus toxoid (Td), antimicrobial therapy, and human antitetanic immunoglobulin (HTIG) were administered, which partially improved the patient’s condition, although she remained dependent on the infusions. On the sixth week of hospitalization, the patient developed status epilepticus which is explained by the magnetic resonance findings that show subacute bi-occipital infarcts caused by hypoxia from the previous crises. Lacosamide therapy reversed the condition and kept the patient free of seizures.It was necessary to carry out a lumbar osteosynthesis which was highly favorable to stabilize the patient's condition. The frequency and intensity of the spasms were gradually reduced, which allowed the gradual suspension of the infusions and the benzodiazepine overlap intravenous (IV) to oral (PO). The patient now has only self-limiting spasms and her maintenance therapy consists of lacosamide and oral clonazepam.This case highlights the importance of considering tetanus in the differential diagnosis even if the vaccination schedule is complete, especially if there are spasms, convulsions, or a history of wounds or bites. It is important to monitor this type of report to reconsider and update the key elements in the prevention, diagnosis, management, and treatment of tetanus; as well as improve access to essential medicines, including the HTIG, and the patient's prognosis in terms of symptom resolution and associated sequelae.