Objective: Increased parent-child communication has been found to strengthen family relationships and reduce adolescent sexual risk behaviors. These processes, however, have not been studied in the sex worker population. Given the fact that the children of sex workers often do not leave the sexual risk environments inhabited by their mothers, the manner in which sex worker mothers shape their children's sexual risk behaviors is crucial to their health and well-being. Family-based sexual health communication interventions (FSHCI) have the potential to change adolescent sexual risk behaviors within the sex work community. Methods: Utilizing a sequential mixed-methods design, this study 1) explored sex worker mothers' normative, behavioral, and control beliefs about sexual health communication with their adolescent children by conducting in-depth qualitative interviews with 34 sex worker mothers, 2) utilized the results of this analysis to design a FSHCI collaboratively with Durbar, a sex worker collective in Kolkata, India, and 3) tested the feasibility and preliminary efficacy of the FSHCI in improving the frequency of mother-children communication about sexual health with a small sample of sex worker mothers. Results: Durbar's collectivizing processes were instrumental in shaping participants' orientation to sexual health communication with their children. FSHCI was successful in changing participants' attitudes and comfort about sexual health communication and the frequency of sexual risk reduction communication. Furthermore, participants' attitudes and perceived behavioral control were significantly correlated with the frequency and comfort of sexual health communication. Conclusion: This is the first study to explore mother-child sexual health communication and test a FSHCI in the sex worker community. Findings support the importance of understanding both community and family level processes in developing and implementing interventions. Findings also support the feasibility of a FSHCI in the sex worker community.