Robots are being used a lot in logistics these days. In line with this trend, more and more researchers are studying robots in logistics. This research identifies the research topics and trends in such research works over the past 20 years. To do this, a latent Dirichlet allocation, a topic modeling approach, was applied. A total of 16 topics are extracted, and the analysis shows that these topics are related to both application areas and the robot-related technologies. Also, the topics regarding the robot-related technologies can be divided into the mechanical ones and the control/optimization algorithms. When it comes to the application areas of robots in logistics, most of the existing research articles are focusing on the transportation part. Finally, the change in the ratio of these 16 topics by year is investigated and summarized.