The note, worth less than $3, depicts an image of a statue of Apollo riding a four-horse chariot atop the Bolshoi Theater, one of Russia's main cultural symbols.
"You can see clearly that Apollo is naked, you can see his genitalia," Roman Khudyakov, a member of parliament for the nationalist LDPR party, told Reuters Television.
"I submitted a parliamentary request and forwarded it directly to the head of the central bank asking for the banknote to be brought into line with the law protecting children and to remove this Apollo."
He said he had been stirred into action when he saw two children looking at the banknote: "The girl screamed at the boy: 'Can you see that I told you, there is a penis here!'. I was shocked, you know."
The call coincides with growing conservatism in President Vladimir Putin's third term, during which he has courted the Russian Orthodox Church. What is widely described as anti-gay legislation has also been passed banning the promotion of "non-traditional" relations to minors.
The Bolshoi itself made headlines by covering the genitalia of the huge Apollo statue with a figleaf when it reopened in 2011 after a scandal-marred restoration that took more than six years and $700 million.
Khudyakov's proposal triggered a wave of satire on the Internet, with some users joking it must have been the first time a lawmaker had seen a 100-rouble banknote as they are reported to deal with much larger sums.
The central bank had no immediate comment.