Erected on 25 March 1992 by Pope John Paul II by the bull Totus Tuus Poloniae populus. The capital of the diocese is in Ełk with the Cathedral of St. Wojciech/Adalbert and Co-Cathedral of St. Alexander in Suwałki and Co-Cathedral of the Blessed Virgin Mary Mother of the Church in Gołdapia. The patron saints of the diocese are the Blessed Virgin Mary, Mother of the Church, St. Wojciech/Adalbert bishop and martyr, and St. Bruno, bishop and martyr.