Vienna had its second bank robbery of 1983 last week, but police report that the number of bank robberies and other serious crimes in the town has dropped noticeably in the past year.

Burglaries dropped more than 60 percent last year, from 145 in 1981 to 66 in 1982, in large part thanks to efforts by the growing Neighborhood Watch program, according to town police Det. Sgt. Joseph Tavares. The statistics include both residential and business burglaries, although most burglaries are residential, he said.

Neighborhood Watch programs in other Northern Virginia jurisdictions have also been credited with helping reduce burglary rates.

Overall, the number of serious felony crimes in the town dropped from 527 in 1981 to 422 in 1982, Tavares said.

The town had two rapes last year, the same as in 1981, but had an increase in assaults, both minor fights and assaults with intent to kill. Alcohol or drugs were involved in most of those cases, Tavares said. There were 25 felony assaults last year compared to 17 in 1981 and 57 misdemeanor assaults compared to 36 in 1981, he said. The town has not had a murder in several years.

Robberies at the town's 22 banks dropped slightly during the past year, from seven in 1981 to five in 1982, Tavares said, but police hope that number will drop even further since virtually all town banks are now installing automatic camera surveillance equipment. Neither of the two banks robbed this year had such equipment, but both are now installing it, Tavares said.

The first robbery, Jan. 6, was solved with the help of Fairfax City police, but last week's robbery of the Providence Savings and Loan is still an open case, Tavares said. Two persons, one in a ski mask, the other with broken front teeth, leaped over bank counters and told tellers to "be cool," Tavares said. They displayed no weapons.

In other town crime, auto theft dropped from 48 in 1981 to 17 in 1982 and grand larceny thefts dropped from 147 in 1981 to 136 last year.