Major General Sergei Moiseyev's wife Irina, 37, later admitted to criminal investigators that she had fired the fatal shots.
The general's daughter found his body, with three bullet wounds in it, shortly after midnight at a hotel where he and his wife had been living temporarily, Interfax news agency quoted a defence ministry spokesman as saying.
Prosecutors said that Irina Moiseyev had fired her husband's unregistered revolver into his chest three times after they had a fight late on Sunday, causing lethal wounds to his head and chest.
The general died instantly.
General Moiseyev, was the commander of the Russian Motorised Infantry Division 20.
A Stechkin revolver and shells were found at the scene of the shooting.
Officers who knew Sergei Moiseyev well told the ITAR-TASS news agency that his wife had been drinking heavily of late.