This article investigates the interpreting needs of Spanish security personnel, their perceptions of their interactions with non-Spanish speakers, and considerations regarding the role of interpreters in their work for the various security forces in Spain. The contextual framework summarises the responsibilities of the Spanish security forces, examines the area of law enforcement as a public service sector in which interpreting is required, and explores legal issues in this field. An indication of the number of potential users of interpreting services in the security forces in the specific region studied (the Canary Islands) is followed by a description of the methodology used. The authors then present the results of their study, which was conducted by means of a questionnaire, drawn up and administered by the authors, on how members of the Civil Guard and the Spanish National and local police forces perceive their language and interpreting needs, as well as their experiences in these fields. As part of this preliminary study, survey respondents were encouraged to share difficulties they had encountered in relation to language mediation, thereby enabling the authors to present an overview of the interlinguistic and intercultural communication difficulties that need to be overcome in these services, as well as service professionals’ impressions of the reality of working with interpreters.