The article presents word formation phenomena characteristic for the nineteenth century Tykocin dialect. The analyses that had been carried out showed that discrepancies with the state of a general language were apparent mostly in the word formation of nouns. A striking feature of the researched material, despite its presence in other dialects, are numerous diminutives that are quite often formed with the use of productive formants in Eastern Slavonic dialects. Moreover, the word formation of nouns revealed the greatest number of features characteristic for dialects of North-Eastern Poland.