Suicide is a significant public health concern, with one million lives lost to it every year. Suicidal ideation and attempts are markers of high risk. The COVID-19 pandemic has had a negative psychological impact on the population. This study aims to describe and analyze the clinical and sociodemographic characteristics of patients who have received medical attention for self-harm attempts in a hospital emergency department, comparing the period before and after the COVID-19 pandemic. This is a descriptive, retrospective study that collected data from medical records of patients who received care for self-harm attempts in the emergency department. The data included cases from 1 January 2018 to 31 December 2022. In total, 529 cases of self-harm attempts were identified, of which 62.8% were female. The number of post-pandemic self-harm attempts significantly increased compared to the period before the pandemic. The most used method for self-harm was medication ingestion. This study revealed that over one-third of the participants had previously attempted suicide. Most self-harm attempts were made by women in the 10–20 or 41–50 age groups, with a history of psychiatric illness and multiple medications. The study results also highlighted an increase in self-harm attempts during the COVID-19 pandemic.