On 18 December 2017, Ratko Mladić filed a motion seeking an extension of time to file his notice of appeal against the ICTY Trial Judgement. Mladić argued that, inter alia, the breadth and complexity of the ICTY Trial Judgement, as well as the extensive underlying record, warrant an extension of time by 150 days beyond the original date upon which his notice of appeal would have been due, namely 22 December 2017.
On 19 December 2017, the then-President of the Mechanism, Judge Theodor Meron, assigned a bench of five Judges to this case before the Appeals Chamber. On 20 December 2017, Judge Meron designated himself as the Pre-Appeal Judge in the case. On 21 December 2017, the Pre-Appeal Judge granted an extension of time for the filing of the notices of appeal and, on 22 March 2018, both parties filed their respective notices of appeal. Following a further extension of time granted on 22 May 2018 for the filing of the appellant’s and respondent’s briefs, the parties filed confidentially their respective appellant’s briefs on 6 August 2018. On 7 August 2018 and 11 September 2018, respectively, the Prosecution and Mladić filed public redacted versions of their appellant’s briefs.
On 18 June 2018, Mladić requested the disqualification of Judges Theodor Meron, Carmel Agius, and Liu Daqun from the appeals bench in this case on the basis of actual or apparent bias. On 20 June 2018, the President of the Mechanism referred the matter to Judge Jean-Claude Antonetti. On 3 September 2018, Judge Antonetti granted Mladić’s requests and, on 4 September 2018, assigned Judges Mparany Mamy Richard Rajohnson, Gberdao Gustave Kam, and Elizabeth Ibanda-Nahamya to replace Judges Meron, Agius, and Liu on the appeals bench in this case. On 12 September 2018, Judge Rajohnson requested to withdraw from the bench in this case and, on 14 September 2018, he was replaced by Judge Aminatta Lois Runeni N’gum.
On 12 September 2018, following Judge Nyambe’s election as the Presiding Judge in this case, Judge Nyambe designated herself as the Pre-Appeal Judge. On 14 November 2018, both parties filed their respective response briefs and on 29 November 2018, their respective reply briefs.
The appeal hearing in the case took place on 25 and 26 August 2020 at the Mechanism's Hague branch.
On 18 February 2021, the President assigned Judge Mustapha El Baaj to replace Judge Kam on the appeals bench in this case after his unfortunate passing.