Thanks, my wife is a Polsih citizen. Are there any restrictions on her purchase since she currently doesn't have a residence in Poland.
Sorry for the typos in my original response (typing to fast!). :)
The most important documents which your wife should possess as proof of her Polish citizenship is the Dowód Osobisty, and a Polish Passport, the former taking precedence. In order to hold or obtain a Dowód Osobisty, one must establish residence in Poland, or, have permission from someone with a current residence to have a Dowód Osobisty using that address. Residence means a flat or home with a legal address and zip code. An empty piece of land will not due, and won't qualify you for a Dowód Osobisty...not even a piwnica (vegetable cellar)!!! ;)
That said, if your wife has all of these documents, there are no restrictions on property purchases in Poland, except for: If you plan to purchase arable farmland in excess of 1 hectare, this qualifies for a 'farm'. In order to buy or own a farm, one must either be a farmer already, OR have 5+ years of farming experience, OR have taken classes in farming. However, that may change in 2012 since every 'foreigner' under the sun will be buying up Polish farmland.