Cases of human trafficking are known to be difficult to prosecute. In this article we identify several issues in the law of evidence that may contribute to these difficulties. We argue for the victims’ rights as an important factor in evidential decisions, coupled with an insistence that such rights cannot trump the defendant’s right to a fair trial. Restrictions on evidence of a witness’s bad character or sexual history should not be interpreted in such a way as to prevent the defence from introducing evidence, or asking questions, that are of substantial probative value, even if they are potentially distressing to witnesses; but such evidence and questioning should be limited to what is necessary for a fair trial. The protection of victims and witnesses may also justify a relatively flexible approach to the admission of hearsay evidence, which avoids prejudging the truth of a witness’s evidence in order to establish that s/he is in fear.