Russia's ambassador to Egypt died suddenly on Monday in a Cairo hospital, the Russian embassy in Cairo said on its social media accounts.
The embassy did not specify the cause of Sergey Kirpichenko's death.
A career diplomat who had served as ambassador to Egypt since 2011, the 68-year-old had also represented Moscow in Libya, Syria and the United Arab Emirates.
Egypt's foreign ministry issued a brief statement expressing its condolences.
Cairo and Moscow have bolstered their strategic and economic ties in recent years under presidents Abdel Fattah al-Sisi and Vladimir Putin.
The flag over the Russian Embassy in Cairo is flying at half-staff in Kirpichenko's memory.