In this study, we investigated through an Internet survey of 508 practicing marriage and family therapists which treatment decisions varied by gender of the client and background variables of therapists. The subjects responded to several typical Internet infidelity scenarios. We varied the gender of the person initiating the infidelity for half of one sample. We also asked the family therapy participants to respond to how they might assess and treat each presenting problem. They also evaluated problem severity, prognosis of the case, number of sessions necessary for treatment, and the extent to which a therapist would focus individually or relationally. Results indicate that there were differences in how therapists assessed and treated clients based on client gender, therapists' age, therapists' gender, how religious therapists reported they were, and the extent of therapists' personal experience with infidelity.