*CALL FOR CONTRIBUTIONS* On behalf of the Scientific and Organising Committees we are pleased to inform you that contributions are now accepted for the Twelfth Workshop on “*Bayesian Inference in Stochastic Processes (BISP12)*” which will be held ONLINE on 27-28 May 2021 (afternoons, Central European Summer Time). _Websit__e_:bisp.imati.cnr.it__ Attendance is free of charge but registration is required. As in the past, the workshop will provide the opportunity to review, discuss and explore directions of development of Bayesian inference in stochastic processes. The workshop has always offered many young researchers the opportunity to present their works in invited sessions. This year the entire invited programme is dedicated to them. Ten presentations by young scientists have been scheduled, followed by an in-depth discussion by senior scholars in the field. *We are now soliciting contributions for a virtual poster session. * We plan to post contributed videos on the workshop website and keep them there for a while after the event, with links to the presenting authors’ websites/emails, so that they can be contacted by interested people. Unfortunately, time constraints will not allow for the presentation of all those works during the workshop but we will allocate short spots for ten contributors to highlight the main findings of their research and few questions & answers. An abstract must be submitted *by 18 April* via the BISP12 website, where the abstract template (Word and Latex) and the guidelines for submission are provided. After submitting the abstract, contributors will receive an acceptance notification email by *30 April* and instructions to upload a pre-recorded video and/or a slide presentation by *15 May*. All presentations will be published on the BISP12 website. The workshop is organised by CNR-IMATI, Institute of Applied Mathematics and Information Technology at the National Research Council of Italy, Milano, www.imati.cnr.it <http://www.imati.cnr.it>. Elisa Varini and Fabrizio Ruggeri Chairs, Organising and Scientific Committees