The shotgun blast was heard just after 2:00 Friday afternoon inside a home along Turner Avenue, near Cedar and Belmont, in southeast Fresno.
Paramedics quickly loaded the 8-year-old boy and rushed him to the hospital.
Police say the boy's dad was doing some work on the gun and thought he had emptied the chamber when it went off.
Police say luckily only a few pellets from the blast hit the boy.
Officers say the man's wife and other kids were inside the home at the time, but were not hit.
Police say these types of accidents happen far too often.
Fresno Police Sgt. Douglas Zavalla says, "You need to realize that whether a gun is loaded or unloaded it should always be pointed in a safe direction, no matter what."
Besides the shotgun that went off, officers also found about a dozen weapons inside a locked safe. Officers ended up confiscating about 6 rifles and 4 to 5 hand guns.
The weapons will be held just until the investigation is over.
Police say detectives will comb over the evidence, but it will ultimately be up the district attorney's office to file charges.
Officers say if anyone is arrested it could take place in a couple of days.