Introduction: Many countries are changing their regulations for prescribing medical cannabis. As gatekeepers, physicians significantly impact patient access to cannabis treatments. It is important to explore how physicians view prescribing cannabis in terms of their existing beliefs, knowledge, possible concerns and personal perceptions. Methods: Individual, semi-structured telephone interviews were undertaken with 14 New Zealand physicians from various specialties. The interviews were thematically analysed using a phenomenological approach. Results: The physician–patient relationship was of extreme importance in making prescription decisions, driven largely by trust in the patient. Barriers to prescribing included concern over possible side effects, the quality and standardisation of medication, uncertainty about indications and equity concerns from the high cost for lower socio-economic patients. Some physicians held concerns over their liability and risks to their reputation if issues arose for patients. Discussion and Conclusion: The way physicians regard prescribing medical cannabis is based on their personal beliefs and knowledge built up over their medical career. It is important that these are taken into consideration in the design of future guidelines to help alleviate uncertainties and reduce barriers for informed prescribing. While our research and previous research find that physicians generally will follow clinical guidelines based on institutional logics (i.e. the standardised approach to medicine), we find that physicians often allow their personal construals to determine their perceptions and prescribing behaviour to a considerable extent when they practice medicine. Our findings have implications for Continuing Medical Education, marketing and regulation for medical cannabis, especially about the wording of guideline adherence.