Online discussion boards are being used increasingly by cancer survivors, highlighting the need for understanding this potentially supportive communication process. Two online discussion boards, a prostate group and a breast cancer group, were studied using mixed methodology of both Grounded Theory and a quasi-numerative approach. Both men's and women's dialogues fell under two themes, information support and emotional support. Information support accounted for 60 per cent of communications in women and 64 per cent in men and emotional support 40 per cent in women and 36 per cent in men. However, there were gender differences in the language styles of these communications. Further research is recommended to understand adequately the emotional content within women's and men's dialogues in the context of breast and prostate cancer discussion boards.