Recently, new agricultural technologies have emerged to increase sustainable food production, often referred to as “Agriculture 4.0.” They consist of more advanced precision agriculture technologies, such as sensors, robotics, and unmanned aerial vehicles (UAVs), which can lead to environmental and economic benefits for farmers and society. Despite the potential benefits of Agriculture 4.0 technologies, the adoption rate remains low. The objective of this study was to gain insight into the factors affecting the adoption of agricultural field robotics and UAVs using a systematic literature review approach that analyzed 23 relevant studies identified from two scientific databases (i.e., Web of Science and Scopus). Data regarding methodological aspects and results were extracted. Even though the current adoption of agricultural robots and UAVs is still limited, farmers seem highly interested. Most studies have used a quantitative approach to study the intention to adopt or the adoption of robotics or UAVs. Surprisingly, few studies have used an existing theory to explain the (intended) adoption. Age, gender, income, education, farm size, perceived usefulness, expected economic and environmental benefits, an attitude of confidence, and the perceived ease of use have been the internal factors most often identified. Meanwhile, the price of the technology, compatibility with other software and equipment, and labor scarcity are the most important external factors.