Joanne Butcher delivered her speech criticising "bogus qualifications" to the Society of Editors conference after a presentation by Simon Bucks, associate editor at Sky News, which outlined the results of a training survey by the society.
The survey found that 37 per cent of editors who responded felt "the standard of entry level journalists has gone down in the last 10 years".
Butcher said in her speech that "there should be better pre-university careers advice" and praised the society for its pledge "to do more to explain the best ways of getting a job in journalism".
But she added that it is "a disgrace to see so many young people completing expensive courses and passing bogus qualifications that simply don’t provide them with the vocational skills they need to get jobs or qualifications that editors have faith in".
"We really do owe it to them to tackle this scandal," she added.
During her speech she also called for a "culture of continuous training".
When asked about the impact of the Leveson inquiry and the future regulation of the press on training, Butcher added that she is hopeful it will not "take out the creativity because we need a broad range of journalists with the tenacity, and almost the maverick status, that we've always enjoyed".
"I hope that it doesn't place any straitjacket on the training and people coming into the industry." Instead she hopes it "will raise the importance of training".
Butcher was also asked about what the NCTJ is doing to equip journalists with editing skills, in response to "newsrooms without sub-editors".
She said "basic editing skills" have been placed "at the heart of the new diploma", adding that many other students will also learn "more specialist skills in the production journalism option".
The NCTJ first launched its Diploma in Journalism, a multimedia qualification, in 2010.