In China, where there are few mental health resources, the majority of HIV-related efforts have focused on medical treatment and transmission prevention rather than psychosocial support. Yet people living with HIV/AIDS (PLWHA) report high levels of psychological distress, especially upon first receiving their HIV diagnosis. We conducted mixed methods research of a qualitative study with (N = 31) individual interviews and 3 focus groups (n = 6 in each group) of HIV-affected participants, and a quantitative survey (N = 200) with individuals living with HIV in Shanghai and Beijing, China. Our qualitative data revealed themes of forms of distress experienced and types of psychosocial support that our participants wished they could have accessed upon diagnosis as well as suggestions for intervention structure that would be most feasible and acceptable. Our quantitative surveys provided further evidence of the high degree of psychosocial distress among recently diagnosed PLWHA. Our findings informed the development of the Psychology Toolbox intervention, a brief CBT skills-based intervention comprising cognitive restructuring, behavioral activation, and paced breathing, designed to be integrated into primary care for recently diagnosed PLWHA. This study describes the intervention development process and contents of each session. Future research should evaluate the intervention for efficacy as well as examine best strategies for eventual implementation and dissemination.