There is growing evidence that nurses in mental health services are likely to be victims of violence or aggression. One of the key difficulties in comparing international findings, however, has been that there has been an inadequate categorization of the types of incident to which staff are exposed. The current study aimed to identify the types of violent or aggressive incidents that staff in Irish Mental Health Services were exposed to within a 1-month long period. A cross-sectional study was undertaken with all nurses working in one of the Mental Health Services in Ireland, serving both an urban and rural population. Data were collected through a questionnaire (Scale of Aggressive and Violent Experiences) adapted from the Perceptions of Prevalence of Aggression Scale. The questionnaire was designed to collect data relating to both personal and professional demographics of the sample as well as experiences of aggressive or violent incidents respondents may have encountered in their work situation. There was a response rate of 31%. Data were analysed utilizing SPSS-11. Both descriptive and inferential analyses were undertaken. The relevant data were subjected to a series of one-way ANOVAS and chi-squared analysis. The findings suggest that nursing staff in this Mental Health Service experienced high levels of verbal aggression, with distinctions obvious between threatening and non-threatening aggression, suggesting discernment in terms of intentionality. Additionally, respondents encountered greater levels of covert or indirect violence or aggression than forms that were overtly directed towards staff. The implications are discussed in relation to both policy and practice.