Cancer pain is a common symptom experienced by patients, caused either by the disease or its treatment. Morphine remains the most effective and recommended treatment for cancer pain. However, cancer patients still do not receive appropriate management for their pain, and under-treatment is common. Lack of knowledge and negative attitudes towards cancer pain and analgesia among professionals, patients and family caregivers are reported as one of the most common barriers to effective cancer pain management (CPM). To systematically review research on the nature and impact of attitudes and knowledge towards CPM, a systematic literature search of 6 databases (the Cochrane library, MEDLINE, PsycINFO, CINAHL, Web of Science and EMBASE) was undertaken in July 2018. Additionally, hand-searching of Google, Google Scholar and reference lists was conducted. The inclusion criteria were adult (18-65 years of age), studies which included attitudes and knowledge towards CPM, studies written in English, published literature only and cross-sectional design. Included studies were critically appraised by two researchers independently using the Joanna Briggs Institute Analytical Cross Sectional Studies Assessment (JBI-ACSSA). A total of 36 studies met the inclusion criteria. The main finding was that among professionals, patients, caregivers and the public there were similar attitudinal barriers to effective CPM. The most commonly cited barriers were fear of drug addiction, tolerance of medication and side effects of opioids. We also found differences between professional groups (physicians versus nurses) and between different countries based on their potential exposure to palliative care training and services. There are still barriers to effective CPM, which might result in unrelieved cancer pain. Therefore, more educational programmes and training for professionals on CPM are needed. Furthermore, patients, caregivers, and the public need more general awareness and adequate level of knowledge about CPM.