In 2006, the National Health Service commenced with assuming responsibility for the delivery and commissioning of mental healthcare services in prisons within the UK. Previous research has indicated that some prison environments may present challenges to the delivery of mental healthcare for prison populations. The present study aimed to explore the experiences of staff working in NHS offender health teams to identify the sources of adversity that frontline staff may encounter when providing mental healthcare in prison settings. The present study also aimed to identify working conditions that may be conducive in facilitating the delivery of mental healthcare in prison settings. Mental healthcare professionals (n = 10) who worked in NHS offender health teams took part in 1:1 semi-structured interviews that were audio recorded and transcribed verbatim. The thematic analysis of the dataset indicated three themes that presented sources of adversity for NHS offender health teams in their delivery of mental health care in prisons; which were 1) location of mental healthcare delivery 2) communication links with stakeholders and 3) prison policies, procedures and legislation. The results of this study have illustrated some of the work-related factors that require attention in order to further support frontline staff in their delivery of mental healthcare in prison settings.