Born in Galicia, Poland. His father, Ben Zion, was a merchant and his mother was a housewife.
In 1914, with the break of World War one his family moved to Vienna and later on continued to Haag and Frankfurt.
Between the years 1919- 1920 Hofstatter attended the FrankfurtScienceSchool.
Eventually the family returned to Vienna in 1921 and stayed there until 1938. In Vienna Osias worked as an accounted.
In 1938 Hofstatter parents was caught by the Gastapo and were sent the Dachau concentration camp. He and his brothers managed to escape and they migrated to Belgium while his fiancée Ana fled to Czechoslovakia.
In 1940, Osais and Ana were reunited in Brussels and they married. A month after the marriage Osais was sent to a concentration camp in France after being accused in spying in favor of Germany. His wife was sent to a different concentration camp where she worked as a seamstress.
In 1942 he managed to reach to Switzerland with the help of his brothers who arrived before him. In Switzerland he worked in a refugee camp and began drawing. In 1943, Hofstatter sent some of his drawing to the United Nations Service Committee in Geneva that decided to let him attend an art school.
Between the years 1942-1946 he attended art schools both in Zurich and Vienna.
After the war ended he received a visa to Vienna and he came back to his wife.
In 1948 the couple moved to Poland and settled in Warsaw, where Osais worked as an art editor of a weekly paper and an art teacher.
In 1959 they immigrated to Israel. They settled down in Holon and Osias worked as a night watchman.
In 1970 he quitted his job and bought a small house near Natanya, where he dedicated his life to his art.
During his lifetime, Hofstatter created over 5000 paintings and drawings, mainly in black ink. In the 60’s he established a new technique of scratching the paper. He created Most of his works after he left his job in 1970. At the same period he began to build a reputation for himself as an artist.
Osais and Ana had no children and after his death in 1994 all his works were given to the Herzelia Museum of Art.
In 1976, Hofstatter won the “Meir Dizingoff” prize in Tel Aviv and in 1991 he were given the “Discount Bank Prize” for an Israeli artist.
“I do not have many dreams; my dreams are my paintings, although I do not know what is going to be in a painting. My dreams a very rare and not significant, I dream that I am alive and it is sufficient for me”.
