System call traces are an invaluable source of information about a program’s runtime behavior, and have been shown to be particularly useful for malware detection in Android apps. However, the paucity of publicly available high quality dataset hinders the development of the field. In this paper, we introduce TwinDroid, a dataset of over 1000 system calls traces, from both benign and infected Android apps. A large part of the dataset is composed of traces from pairs benign and infected apps, identical apart from the inclusion of malware in the latter. This makes TwinDroid an ideal basis for security research, and an earlier version of TwinDroid has already been used for this purpose. In addition to a dataset of traces, TwinDroid includes a fully automated traces generation pipeline, which allows users to seamlessly generate new traces in a standardized manner. This pipeline will allow the dataset to remain up-to-date and relevant despite the rapid pace of change that characterizes Android security.