The Rt Rev Joseph Devine, the Bishop of Motherwell, also launched an attack on the Green Party, accusing it of "masquerading" as an environmental organisation while following an anti-religious, pro-gay agenda.
Devine, who also equated abortion with the deaths of British prisoners of war in Japanese slave camps, made his comments in a statement issued today in the wake of a case in which two Christian pro-life campaigners were arrested after unfurling 7ft banners showing aborted foetuses outside a clinic in Brighton.
Andrew Stephenson, 37, and Kathryn Sloane, 21, were cleared of public order offences after a judge dismissed the case.
Referring to the case, Devine said: "As other commentators have observed, such images should not be suppressed from the public consciousness any more than pictures of famine or the reality of war. If we cannot face the pictures, how can we conceive of endorsing the reality?
"I have no doubt that the publication of the photographs of the victims of Auschwitz and the Burma Railway brought home the horrors of such evil catastrophes far more effectively than a million pleading words. Two hundred thousand abortions take place in Britain each year. Why is the pro-choice lobby so desperate to hide the truth about abortion from the public?"
Devine also criticised police for bringing the case to court, saying they would perhaps "benefit from professional guidance" as to their interpretation of the Public Order Act.
Pro-choice campaigners yesterday branded his comments as "the lowest of the low".
Clare Murphy, spokeswoman for the British Pregnancy Advisory Service, said: " I think most people would find it utterly despicable to compare abortion to the Holocaust. It is deeply insulting to the millions of Jewish people who died during the second world war.
"It is hugely inflammatory. I can't imagine anyone would feel that comparing abortion to the Holocaust is a useful or pertinent analogy."
Murphy said the use of images of abortion was not the issue, but displaying them outside a clinic was intended to cause distress to pregnant women entering and leaving.
"It is perhaps time for those who invoke morality to think whether it is moral to basically intimidate pregnant women in this way," she added.
Ann Henderson, chair of campaign group Abortion Rights, said: "It is completely inappropriate for a member of the Catholic community to be making statements which appear to condone harassing behaviour."
Meanwhile, Devine was equally outspoken on his views on the case of Christina Summers, a Christian councillor in Brighton who was expelled from the Green Party this month after voting against same-sex marriage, defying party policy.
He said: "At last the mask has been torn away from the duplicitous Green Party that masquerades as an environmentalist organisation.
"For years it has operated under the cover of 'saving the planet' while publicly playing down its anti-religious faith, anti-democratic agenda."
Devine also claimed there is a perception the leader of the Greens in Scotland, Patrick Harvie, is more concerned with championing a "gay agenda" than environmental issues.
"To seek to coerce loyalty to the party above loyalty to individual conscience calls to mind the worst kind of totalitarian politics," he added.
Harvie said: "People like Bishop Devine need to catch up with the fact society has moved on from the days of homophobia in politics.
"The only parties that espouse the kind of views about LGBT rights that Bishop Devine has are the BNP and UKIP."
He added: "I find the comments slightly absurd. If you look at the track record of Green parties around the world, you see a very clear, consistent, strong, environmental, economic and social justice agenda.
"To suggest that because we support gay rights we are not promoting green economics or green politics is nonsense."
A spokesman for the British Humanist Association described Devine's comments as "bizarre and intemperate remarks" close to parody.
He added: "To compare abortion with genocide in particular betrays a twisted lack of moral perspective and the inflammatory language degrades political debate."
The abortion row follows a dispute earlier this year when the new Catholic Archbishop of Glasgow Philip Tartaglia appeared to link the death of Labour MP David Cairns from pancreatitis with the fact that he was gay.