Spiritual care is an important dimension of palliative care (PC) and a facet of holistic care that helps ill people find meaning in their suffering and lives. This study aims to: (a) develop and test the psychometric properties of a new instrument, Perceived Barriers to Spiritual Care (PBSC); (b) explore participants’ perceptions of how prevalent those (pre-identified) barriers are; and (c) examine the association of their personal and professional characteristics with those perceptions. A descriptive cross-sectional study was carried out using a self-reporting online survey. In total, 251 professionals registered with the Portuguese Association of Palliative Care (APCP) completed the study. The majority of respondents were female (83.3%), nurses (45.4%), had more than 11 years of professional experience (66.1%), did not work in PC (61.8%), and had a religious affiliation (81.7%). The psychometric assessment using PBSC provided sound evidence for its validity and reliability. The three most common perceived barriers were late referral for palliative care (78.1%), work overload (75.3%), and uncontrolled physical symptoms (72.5%). The least commonly perceived barriers were different spiritual beliefs among professionals (10.8%), differences between the beliefs of professionals and patients (14.4%), and the shame of approaching spirituality in a professional context (26.7%). The findings show there is some relationship between sex, age, years of professional experience, working in PC, having a religious affiliation, the importance of spiritual/religious beliefs, and responses to the PBSC tool. The results highlight the importance of advanced training in spirituality and intervention strategies. Further research is needed to properly study the impacts of spiritual care and establish outcome assessments that accurately reflect the effects of the various spiritual care activities.