Career
Spartak Pleven
After emerging through Levski Sofia"s youth system, Plamen Nikolov made his professional debut in the second level with Spartak Pleven, the club from his home town. He made his team début on 7 August 2004, in an 0–0 draw against Rilski Sportist Samokov. On 6 October 2004 Nikolov scored his first goal in an 6–0 drubbing of amateur side Botev Lukovit of Bulgarian Cup.
Plamen quickly became part of the main team and for two seasons earned 53 appearances, scoring two goals.
Litex Lovech
In June 2006, Nikolov agreed a deal to sign for Litex Lovech for an undisclosed fee. He has made his debut for Litex in Rilski Sportist match on 13 August 2006 as an 85th-minute substitute.
During his first season in Litex, Nikolov found regular starting positions in defence hard to find. He played only 5 matches in the domestic league.
In 2007-2008 A PFG season coach of Litex Miodrag Ješić decided to put Nikolov into the starting line-up as center back.
In this season, he earned 22 appearances playing in the A PFG, scored one goal. In the final against Cherno More he played 90 minutes. Football Club Tom Tomsk
In February 2012 Nikolov signed for Football Club Tom Tomsk on loan until the end of the season, before joining the club permanently in the summer of the same year.
Return to Litex Lovech
In January 2014 Nikolov re-signed for Litex Lovech.
Botev Plovdiv
On 30 July 2014 Plamen Nikolov signed a contract with Botev Plovdiv until the end of the season. On 16 May, Nikolov was sent off with a direct red card after a conflict with Toni Silva from CSKA Sofia, who was also sent official
On 17 June, Nikolov extended his contract with Botev until the end of 2015-2016 season. Nikolov terminated his contact on mutual agreement and left Botev Plovdiv in January 2016.