BACKGROUND: There is no agreed way to measure the effects of social accountability interventions. Studies to examine whether and how social accountability and collective action processes contribute to better health and healthcare services are underway in different areas of health, and health effects are captured using a range of different research designs. OBJECTIVES: The objective of our review is to help inform evaluation efforts by identifying, summarizing, and critically appraising study designs used to assess and measure social accountability interventions' effects on health, including data collection methods and outcome measures. Specifically, we consider the designs used to assess social accountability interventions for reproductive, maternal, newborn, child, and adolescent health (RMNCAH). DATA SOURCES: Data were obtained from the Cochrane Library, EMBASE, MEDLINE, SCOPUS, and Social Policy & Practice databases. ELIGIBILITY CRITERIA: We included papers published on or after 1 January 2009 that described an evaluation of the effects of a social accountability intervention on RMNCAH. RESULTS: Twenty-two papers met our inclusion criteria. Methods for assessing or reporting health effects of social accountability interventions varied widely and included longitudinal, ethnographic, and experimental designs. Surprisingly, given the topic area, there were no studies that took an explicit systems-orientated approach. Data collection methods ranged from quantitative scorecard data through to in-depth interviews and observations. Analysis of how interventions achieved their effects relied on qualitative data, whereas quantitative data often raised rather than answered questions, and/or seemed likely to be poor quality. Few studies reported on negative effects or harms; studies did not always draw on any particular theoretical framework. None of the studies where there appeared to be financial dependencies between the evaluators and the intervention implementation teams reflected on whether or how these dependencies might have affected the evaluation. The interventions evaluated in the included studies fell into the following categories: aid chain partnership, social audit, community-based monitoring, community-linked maternal death review, community mobilization for improved health, community reporting hotline, evidence for action, report cards, scorecards, and strengthening health communities. CONCLUSIONS: A wide range of methods are currently being used to attempt to evaluate effects of social accountability interventions. The wider context of interventions including the historical or social context is important, as shown in the few studies to consider these dimensions. While many studies collect useful qualitative data that help illuminate how and whether interventions work, the data and analysis are often limited in scope with little attention to the wider context. Future studies taking into account broader sociopolitical dimensions are likely to help illuminate processes of accountability and inform questions of transferability of interventions. The review protocol was registered with PROSPERO (registration # CRD42018108252).