The call is permanently open. All the submitted papers are peer reviewed between January and April each year.
We are now receiving papers for the volumes:
38 (2019): 28th April 2019: Theories of Vision: Augustine of Hippo and the Augustinian Tradition
39 (2020): 31st March 2020: Finzione nel discorso filosofico medievale
40 (2021): 31st March 2021

Publication schedule:

39 (2020): online release: July 2020.
38 (2019): online release: April 2020.
37 (2018): Scire naturam: online release: November 2019
36 (2017): released online: http://ojs.letras.up.pt/index.php/mediaevalia/issue/view/392
35 (2016): released online: http://ojs.letras.up.pt/index.php/mediaevalia/issue/view/214
24 (2005): released online 08.2019: https://ojs.letras.up.pt/index.php/mediaevalia/issue/view/73

At last we expect to be paired during the 1st semester 2020.