He was born in 1880 in the family of the Polotsk clergyman. He graduated from St. George's University. Prior to the revolution he worked as a physician in Polotsk. From 1920 he held the post of therapeutist at the Polotsk People's Hospital. Simultaneously, he took the reception in the city dispensary.
In 1921 N.D. Gnedovsky was awarded the title of "Hero of Labor" as one of the few public activists who participated in the work of the commissions and events of the District Health Department. He died in 1921. He was buried in Polotsk.