This exploratory study aimed to examine online communications between contact reality and non‐contact fantasy child sex offenders (CSOs). This research wanted to ascertain whether it was possible to differentiate between these offenders based on the content of their online communications, something which has not previously been examined. The sample consisted of five contact reality and seven non‐contact fantasy offenders, all convicted of a Child Sex Offence. Content analysis revealed 26 them. Results showed that non‐contact fantasy offenders discussed Adult sexual relationships significantly more than contact reality offenders. All other comparisons were non‐significant. The themes were then grouped into five higher order themes: (i) Adult relationships, (ii) Child sexual interest, (iii) Media, (iv) Sexual self, and (v) Rapport. The average largest proportion of the online communication related to Child sexual interest (34%) followed by Rapport (28%). There were no significant differences between the two types of offenders in relation to these five higher order themes. Explanations for the findings are discussed with implications for police investigations. Copyright © 2015 John Wiley & Sons, Ltd.