This article is dedicated to a conceptualization of the accident in the Substantive Criminal Law of the Republic of Moldova and Romania. In the realm of this research the author has performed a detailed analysis of the modern penal doctrine as well as of the judicial practice in the matter of the accident. The authors has begun their investigation being defined the concept of culpability as an indispensable condition of the criminal liability, analysis of the signs of a criminal misdeed committed without guilt, clarification of the notions of ‘accident’ and ‘force majeure’, as well as correlation between them. Being elucidated the legal nature of the accident; authors have synthesized conditions of operation of this cause of defense. A special attention is afforded to the feature of unpredictability of the accident. In order to make clear some ideas, the authors have brought several cases from the judicial practice of the Supreme Court of Justice of Romania, being formulated some conclusions useful for the science of the Substantive Criminal Law.