This study was done to examine the psychosocial effects of sexual partner seeking via social media accounts among adolescents; and assess whether sexual partner seeking matches with sexual orientations among adolescents using social media accounts in Dar es Salaam. Correlational research design and questionnaires were used to collect data among 264 adolescents in universities and 234 adolescents in secondary schools, who were sampled using stratified sampling technique. The obtained data were subjected to descriptive and correlational analysis and test using SPSS IBM Version 20 and presented in tables. The results indicate that sexual partner seeking via social media accounts has enhanced adolescents to be sexually overambitious to the extent of engaging in risky sexual debuts, disclosure of adolescents’ privacy/secrecy, demoralization due to postage of naked pictures or their sex videos after breaking up with the partners, together with intimidations, cyber-sexual abuse and sexual insults after meeting with untrustworthy sexual partner seekers. They also indicate that sexual partner seeking is relative to sexual orientations of adolescents as driven by self-interests and sexual feelings. Therefore, it is concluded that sexual partner seeking via social media accounts is done under risky circumstances and affects the psychosocial wellbeing of adolescents. It is also recommended that more studies should be done in order to inform about coping mechanisms for the adolescents who encounter the psychosocial effects after meeting sexual partner seekers via social media accounts.