| 2025-07-19 | UFC 318: Holloway vs. Poirier 3 | Light Heavyweight | Jimmy Crute def. Marcin Prachnio | Submission (armbar) | 1 | 4:41 |
| 2024-07-27 | UFC 304: Edwards vs. Muhammad 2 | Light Heavyweight | Modestas Bukauskas def. Marcin Prachnio | Submission (arm-triangle choke) | 3 | 3:12 |
| 2024-02-10 | UFC Fight Night: Hermansson vs. Pyfer | Light Heavyweight | Marcin Prachnio def. Devin Clark | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2023-07-08 | UFC 290: Volkanovski vs. Rodríguez | Light Heavyweight | Vitor Petrino def. Marcin Prachnio | Submission (arm-triangle choke) | 3 | 3:42 |
| 2023-02-18 | UFC Fight Night: Andrade vs. Blanchfield | Light Heavyweight | Marcin Prachnio def. William Knight | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2022-04-23 | UFC Fight Night: Lemos vs. Andrade | Light Heavyweight | Philipe Lins def. Marcin Prachnio | Decision (unanimous) (29–28, 29–28, 29–28) | 3 | 5:00 |
| 2021-06-26 | UFC Fight Night: Gane vs. Volkov | Light Heavyweight | Marcin Prachnio def. Ike Villanueva | TKO (body kick) | 2 | 0:56 |
| 2021-01-24 | UFC 257: Poirier vs. McGregor 2 | Light Heavyweight | Marcin Prachnio def. Khalil Rountree Jr. | Decision (unanimous) (29–28, 29–28, 29–28) | 3 | 5:00 |
| 2020-08-22 | UFC on ESPN: Munhoz vs. Edgar | Light Heavyweight | Mike Rodríguez def. Marcin Prachnio | KO (elbow and punches) | 1 | 2:17 |
| 2018-09-15 | UFC Fight Night: Hunt vs. Oleinik | Light Heavyweight | Magomed Ankalaev def. Marcin Prachnio | KO (head kick and punches) | 1 | 3:09 |
| 2018-02-24 | UFC on Fox: Emmett vs. Stephens | Light Heavyweight | Sam Alvey def. Marcin Prachnio | KO (punch) | 1 | 4:23 |