Nemov grew up in Tolyatti, where he began gymnastics at the age of six years. At fourteen, he was inducted into the Soviet junior team and trained from then on in the national training center at the "Round Lake ", near Moscow.
His first international appearance in the seniors had Nemov. At the World Championships in 1993 in Birmingham, where he finished fifth on the floor His first title he won at the 1995 World Championships in Sabae at the jump.
At the Olympic Games in Atlanta in 1996, he became Olympic champion with the team and at the jump, but the profit of the multi struggle just missed and had to admit defeat to the Chinese Li Xiaoshuang. Nevertheless, he was not only a fan favorite of the Olympic gymnastics competitions, but with six medals even the most successful gymnasts in the games.
After a shoulder operation in 1997, he could not easily do gymnastics on the rings first. The more he surprised at the Olympic Games 2000 in Sydney, where he was again able to win six medals, including gold medals in the individual all-around and high bar.
Both titles he could not defend at the Olympic Games in Athens in 2004. While he was in the bar final, there was, however, only fifth. The only visible to the public error Nemows was a lunge after the landing of the outlet. This led to a minute-long whistling in the hall, the audience quieted Nemov. Although his rating was corrected by the Chief Judge of 9.725 to 9.762 points for a medal win but not enough so. Nemov himself criticized not the judges in public.
After the 2004 Olympics Nemov ended his active career.
Nemov is married and has one son.