If smallholder farming households in Papua New Guinea achieve higher crop productivity levels, progress will be made along several dimensions of the development vision for PNG – increasing GDP for the agricultural sector and the overall economy; driving growth, diversification, and transformation of local rural economies; improving food consumption; and reducing poverty. In this paper, we examine recent data on yields for the most important crops grown in PNG, assess what yields might be achieved based on productivity data from areas of Indonesia with similar growing conditions, and sketch where policy reforms could provide incentives and access to technologies to achieve higher crop yields by all farmers across PNG. While yield gaps – the difference between the crop yields farmers commonly obtain and what they might realize with optimal crop management and the use of high-yielding varieties – could not be estimated for the main cash crops, rough estimates could be made for the main staple food crops. These vary by crop. The yield gap for sweet potato is the smallest – actual farmer yields are between onequarter to one-third less than attainable yields for the crop. Yield gaps for taro, Chinese taro, cassava, and yam are between 40 and 60 percent of what might be attained. Banana shows the largest yield gap at only about a quarter of the productivity levels that might be achieved under intensive cultivation. Strong agricultural research efforts coupled with effective agricultural extension systems are critical if farmers are to maximize the returns that they obtain from their crop production and reduce these yield gaps. Moreover, the challenges that farmers face in their crop production today are not necessary the same challenges that they will face in the future. Climate change will introduce new production challenges, whether through changes in rainfall and temperature patterns or through increased incidence of pests and diseases that are better able to flourish under the changed climatic conditions. Moreover, increased trade in both cash crops and food crops heightens risks from introduced pests and diseases that so far have not affected farming in PNG. To enable farmers in PNG to adapt and surmount to these new challenges similarly will require continuous research and effective communication to farmers of the improved techniques and technologies that will enable them to manage them sustainably and profitably.