My ancestors from Poland were ethnic Jews

Hi. It is highley likley that my ancestors from Poland were ethnic Jews. My Great grandfather was very dark complected, almost "arabic" looking and he lived in Nowogrod, which more than half the population was Jewish. His father came from Hungary to Nowogrod, and their surname was Zawistowski, but it is beleived that they adopted it upon arrival in Poland. Although when they immigrated to America they threw away their Judaism, and names changed. Although they openly practiced catholicism, my uncle, who was alive when they were still alive, recalls opening a chest of theirs which contained a menorah. Also, after my great grandfather died, many strangers that my uncle never recalled seeing came to the house to mourn (for seven days), which is known as sitting shiva. Also, a peice of his clothing was torn and my great grandmother pinned it to her shirt. My family today practices Judaism. How likley is it that my great grandfather was Jewish?

Very likely. The penultimate sentence kind of clinches it.

I often do wonder if I have any Jewish ancestry from Poland. My parents just don't seem to know much. :-(

you most likely do.

I never knew about my dad's jewish family (that is, his grandparents and their ancestors) until my mom told me around 5 years ago, or that his grandmother was also a 'wiedźma'. :)

I think the handle jewboy 16 kind of clinches it.

It is said that genetically jews, and arabs are almost alike.

news.bbc.co.uk/2/hi/sci/tech/742430.stm

Congrats!

Possibly Nowogródek (in Poland before 1939). There is also the big Russian city of Nowogród, not that far from St. Petersburg (or Leningrad under the Soviet Union).

Could have been. My mother's family is Polish and they are darker skinned. I"ve always been mistaken for Italian or Hispanic. While doing some family research we found some Jewish ancestry from Poland, which we didn't even know existed in our family line. So it is very possible. I believe there were converts at times.

Zawistowski is one of the local minor noble families who were administrators for land need Bialystock, poland, which is known for their jewish population. so it seems liikely they took the name for a variety of reasons