Background There are around 19 000 fatal injuries annually in Argentina. Since 1983, deaths due to self inflicted (SI) injuries were more frequent than Interpersonal (IP) fatal injuries. However around 12–14% of injuries were classified under Undetermined intention (UD).

Objective To identify characteristics of undetermined causes of deaths and to describe the relationship between the mechanism of injury by age and sex associated with intentionality of the event.

Methods Data on mortality health statistics from 1996 to 2010 were used (N=125 832). Included Mechanism were: Falls, Drowning, Other threats to breathing (OTB), Fire, Firearm, Sharp object (SO), Machinery, Gases, Pesticides, Other poisons (OP). A factorial analysis of multiple correspondences and cluster analysis with one mixed classification and centroid was made. Active variables: age, sex, mechanism, occurrence place. Illustrative variables: intentionality.

Results The five first axes were conserved (36.75% of the inertia). A global typology was obtained in five classes which non exclusive characteristic modalities were:

Class1 (N=41 870): Firearm, SO, OP; 10–50-years-old; Street, Unspecified place; IP or UD. Class2 (N=7781): Falls, Gases; Female; older than 60 years; Home; Unintentional (U). Class3 (N=43 596): OTB, Gases; Male; older than 40 years; Home; (SI). Class4 (N=17 262): Fire, OP; younger than 10 or older than 60-years-old; Unspecified place; (U). Class5 (N=9966): Drowning; Male; younger than 20 years; Other specified place; (U). 57% of UD was in class1, and 20% in class3 (p<0.0001)

Conclusions The redistribution of undetermined causes of death according the injury mechanism, age and sex could be useful to obtain more accurate information of specified intentional deaths.