In a setting with restrictive firearm laws, prevention of firearm deaths is challenging. Around 100 firearm suicides occur annually in Sweden, representing the most common manner of death from firearm use. In order to explore a possible correlation between firearm suicides and firearm availability, legality of firearm possession, and demographic and geographical factors, all firearm suicides in Sweden among adults during the years 2016–2017 were studied. Data were collected from the National Board of Forensic Medicine and the Swedish Police. In total, 221 firearm suicides were found. Most victims were male (99%) and half (49%) were ≥65 years old. Firearm suicide rates were positively correlated with firearm ownership rates in Swedish counties. Legal firearms (80%) and long-barreled firearms (76%) predominated in the overall material, but illegal firearms were common among young suicide victims (18–29 years) and in urban areas. Prevention work needs to emphasize strategies to reach firearm owners at risk of suicide. Local health and healthcare-related factors, as well as geographic and demographic factors, should be considered in tailoring such strategies.