Ecological momentary assessment (EMA) gathers respondent data on affective, behavioral, and contextual experiences as close in time to those experiences as possible. Potential advantages of EMA in aging research include reducing memory biases and gathering intra-individual data, yet there is little understanding about implementation. The goal of this critical review was to assess the feasibility and applications of EMA in psychological and behavioral research on aging. Through a comprehensive search of the online electronic databases, Psycinfo and Pubmed, for English-language peer-reviewed journals published between 1990 and 2007, we identified 40 articles using EMA methods in older adults. Studies sampled participants between five times per day over one day to once a week for 210 days. Samples were generally not cognitively impaired, evenly split between healthy and clinical populations, and only 6 of 40 studies focused on psychiatric diagnoses. The most common assessment content solicited ratings on affect (n=15), activities of daily living (n=12), physical activities (n=10), and social exchanges (n=8). A total of 90% of the studies that reported compliance reported rates over 80%. Uses of EMA varied widely, with research goals including validation of global measures, detection of subtle treatment effects, and for testing hypotheses about causal intra-individual relationships. Although these measures appear feasible and useful in aging research, recommendations for future studies include adapting measures to enable data collection among older participants with cognitive impairments and/or psychopathology, along with greater use of electronic data capture to improve compliance and increase ease of implementation.