Recent years have seen an increasing number of cases of intentional poisoning with sodium nitrite. This is due, in part, to its inexpensive and readily available nature, and to the growth of social media. This paper briefly reviews the toxicity of sodium nitrite and the mechanism of death associated with its consumption and then presents a case of the fatal sodium nitrite poisoning of two sisters within a few hours of each other. It goes on to discuss both the growing problem of mental disorders, particularly among young people, and the potential diagnostic difficulties associated with sodium nitrite poisoning. It also addresses the approach to determining the manner of death, which may not be evident to the investigator; an accurate investigation is, of course, essential, as mistakes can result in the failure to identify the actual perpetrators and even lead to false accusations of guilt.