Parties to the conflict in Yemen have continued to commit serious violations, undermining Yemenis ability to live, in blatant disregard of basic rules of international law and humanitarian standards. And while Yemenis were racing against time to overcome the plight of the war in 2021, the pace of hostilities escalated and violence expanded in the governorates, killing hundreds of civilians. The war has left poor conditions for the residents of those areas. This has caused the displacement of tens of thousands of them. The escalating violence has also caused widespread damage to vital infrastructure, including hospitals and service facilities.In the body of this annual report, Mwatana for Human Rights provides an extensive review of particular violations that occurred and the overall human rights situation in Yemen during 2021. Mwatana, whose work covers most Yemeni governorates, has documented––through fact-finding, evidence examination, and detailed research––hundreds of incidents that violate international humanitarian law (IHL) and international human rights law (IHRL). Some of these violations may amount to war crimes. The report presents some incidents as examples, shedding light on different types of abuses committed by the warring parties.In order to draft this report, Mwatana for Human rights conducted investigative field research, including thorough investigations and direct inspections of the sites where attacks and incidents took place. Throughout 2021, Mwatana interviewed witnesses, relatives of victims, survivors, medical and human rights workers, and examined documents, evidence, photos, videos, and other physical evidence. During 2021, Mwatana documented (699) incidents, which killed (440) and injured (675) civilians, and include incidents of disappearance, detention, and torture of (494) civilian victims.The incidents and patterns of violations of international humanitarian and human rights law included in this report represent examples of the most prominent ones documented by Mwatana during 2021. In no way do they represent all the incidents and patterns that occurred in Yemen that year. Mwatana continues to document violations and abuses that have occurred since the beginning of 2022.