St. Casimir Church serves as the sanctuary of Lithuanian immigrants and their families in the West coast. It was established as a mission church for those who fled the homeland during the Russian occupation. Today, St. Casimir Church brings Christ to a diverse community of immigrants. It respects and welcomes the traditions and religious practices of other nationalities such as Filipinos and Latinos in the light of the new evangelization.

Aside from its unique Baltic architecture, it houses an exact replica of the image of Divine Mercy, a close copy as St. Faustina described to a painter how she saw Jesus. The original was stolen, smuggled and forgotten during the Russian occupation until it was recently installed at the Holy Trinity Church in Vilnius.

Above the main door is the image of Our Lady of the Gate of Dawn. In 1702, when Vilnius was captured by the Swedish army during the Great Northern War, Our Lady of the Gate of Dawn came to her people's rescue. 

Inside is another image of Our Lady of Siluva. It is believed that the Blessed Mother appeared in the village of Siluva that brought Lithuanians back to their Catholic faith during the tide of Reformation heresy, two  hundred fifty years before Lourdes and Fatima.

St. Casimir was the second son of King Casimir IV and Elizabeth of Austria. He rejected his princely rights and lifestyle, instead he preferred ordinary comforts, enjoyed the company of common people, spent hours in prayer, slept on the floor and helped the poor. He refused to assume the throne of Hungary and his father sent him to exile. He remained celibate until he died at the age of 23 from lung disease. He was buried with his favorite song, "Daily, Daily Sing to Mary."