Inner-city health research can be challenging because it deals with vulnerable populations and sometimes puts investigators in difficult situations. Some challenges are methodological, including selecting the optimal research design, implementing effective methods of recruitment and retention, and determining the best approach to data analysis. Other issues are practical, including addressing potential biases in social research; dealing with conflicting research agendas among investigators, community agencies, and funding agencies; and disseminating research findings effectively. Another set of issues relates to the ethical conduct of research, including ensuring privacy, maintaining confidentiality, and obtaining consent that is informed, not coerced, and not influenced by undue inducements. Throughout the research endeavor, the inner-city health researcher must carefully balance the roles of investigator, advocate, activist, and caregiver.