The *Twelfth Workshop on Bayesian Inference in Stochastic Processes* was successfully held on 27-28 May, 2021. We inform you that the entire event has been recorded and videos of the invited talks with discussions as well as the virtual posters are uploaded to the BISP12 website: https://bisp12.imati.cnr.it/ <https://bisp12.imati.cnr.it/> They will be available for some months. If you have questions or comments for the speakers, you are warmly invited to contact them. We had 10 junior invited speakers and 10 more senior discussants (within parentheses): •    Atilla Ay, USA (Melike Baykal-Gursoy, USA) •    Clara Grazian, Australia (Maria Concepcion Ausin, Spain) •    Andrew Holbrook, USA (Katja Ickstadt, Germany) •    Kaoru Irie, Japan (Sylvia Frühwirth-Schnatter, Austria) •    Roi Naveiro, Spain (Mike West, USA) •    Giovanni Rebaudo , USA (Bernardo Nipoti, Italy) •    Claudia Solis-Lemus, USA (Nicholas Polson, USA) •    Stéphanie Van Der Pas, The Netherlands (Antonio Lijoi, Italy) •    Andi Wang, UK (Giacomo Zanella, Italy) •    Paul Wu, Australia (David Banks, USA) We also had seventeen contributors who uploaded 20-minutes virtual posters and short videopresentations. We would also like to thank speakers, discussants and participants for the success of BISP12. Best regards and see you at the next BISP13 workshop in 2023. Elisa Varini and Fabrizio Ruggeri Chairs, Organising and Scientific Committees