Joanne Pinder, 22, of 29 Titmus Dr., was charged with fifth degree grand larceny.
The victim, an 86-year-old Bellport man, noticed that his valuable watch had been replaced by a similar but less valuable watch, and notified authorities, police said.
The watch was stolen from him on April 12, police said.
Fifth Precinct officers and detectives involved in the investigation arrested Pinder and recovered the watch, police said.
Pinder, who was also charged with aggravated unlicensed operation of a motor vehicle, was to be arraigned on the charges Tuesday in First District Court, Central Islip.