The overall aims of this thesis were to investigate psychological and behavioral effects of receiving cancer genetic counseling for breast, ovarian and colorectal cancer and/or with a family history of these cancer types and to determine whether counselees’ informational needs were met. Study I was performed 3-7 years post-counseling. Participants (n=214) reported a relatively high level of anxiety but a low level of depression compared to cancer patients in general. However, there was no indication that the distress experienced was due to the counseling. Moderate changes in life and family relations, high level of adherence to recommended controls and satisfaction was reported. Study II was a randomized control trial (RCT) intervention study which involved 147 counselees. An increase in the level of knowledge and correct estimation of personal risk was reported in both the intervention and control groups, although this increase declined at later follow-up. Enhanced information led to significantly greater satisfaction with the given information, and the way of informing relatives. Most counselees had shared information with their at-risk relatives. Study III focused on sharing information with at-risk relatives among participants in study II and their relatives (n=81). Counselees were interviewed and answered a questionnaire, whilst their relatives only answered the questionnaire. Counselees reported positive/neutral feelings about communicating genetic information and mostly interpreted their relatives’ reactions as positive/ neutral. Also, approximately 50% of relatives reported positive/neutral reactions and were generally satisfied with the received information. Study IV was conducted in Sweden and Norway based on 235 counselees. Counselees expected counselors to be skillful and thoughtful, take them seriously and provide risk estimations and medical information. Most important issues to counselees were satisfactorily addressed by the counselors. Analyzing importance rankings resulted in five categories of needs: a need for facts, caring communication and medical information, need for understanding and support in sharing genetic information, practical care and medical/practical information. In conclusion, no adverse psychological or behavioral effect on counselees was observed. Apparently, genetic counseling is managed properly and counselors successfully address counselees’ needs. Providing extended information does not seem necessary, however, tailoring information to individual counselees needs may create a more effective counseling.