The authors examined the online construction of identity and sexuality in a large sample of conversations from monitored and unmonitored teen chat rooms. More than half of the 583 participants (identified by a distinct screen name) communicated identity information, most frequently gender. In this way, participants compensated for the text-based chat environment by providing information about themselves that would be visible and obvious in face-to-face communication. Sexual themes constituted 5% of all utterances (1 sexual comment per minute); bad or obscene language constituted 3% of the sample (1 obscenity every 2 minutes). Participants who self-identified as female produced more implicit sexual communication, participants who self-identified as male produced more explicit sexual communication. The protected environment of monitored chat (hosts who enforce basic behavioral rules) contained an environment with less explicit sexuality and fewer obscenities than the freer environment of unmonitored chat. These differences were attributable both to the monitoring process itself and to the differing populations attracted to each type of chat room (monitored: more participants self-identified as younger and female; unmonitored: more participants self-identified as older and male).