Noncommunicable diseases (NCDs) kill 40 million people each year and are the cause of 70% of global deaths annually. Proximal risk factors include tobacco use, physical inactivity, the harmful use of alcohol and consumption of unhealthy food, which are shaped by the social and economic conditions of daily life, known as the social and commercial determinants of health. It is well recognised within the global health community that policy coherence across all levels of government at the national and international level is required to address NCDs. To date, however, there has been little coherence between health and trade policy, which directly affects access to unhealthy or healthy commodities. This paper explores policy actors' views of the challenges in achieving coordinated and coherent NCD policy across health and trade sectors. Drawing on interviews (n = 18) with key policy actors and using a policy framework that focuses on ideas, power and the 'deep core' of neoliberalism, we identify the role of competing frames, power asymmetries and interests in constraining policy coherence. We also find differences between NCD risk factor domains. Tobacco control was highlighted as one area of generally successful coherence internationally. In contrast, alcohol and nutrition were identified as areas with little coherence. Industry power, the role of evidence, presence of absence of a treaty, the extent of coordinated advocacy and leadership by intergovernmental organisations were key factors influencing coherence. In light of these constraints, the role of advocacy by non-governmental organisations was highlighted as the key for much-needed policy change.