OBJECTIVES: To develop and examine the validity and reliability of a targeted geriatric assessment (TaGA) for busy healthcare settings. DESIGN: The TaGA was developed through the consensus of experts (Delphi technique), and we investigated its construct validity and reliability in a cross-sectional study. SETTING: Geriatric day hospital specializing in acute care in Brazil. PARTICIPANTS: Older adults (N = 534) aged 79.5 ± 8.4, 63% female, consecutively admitted to the geriatric day hospital. MEASUREMENTS: The Frailty Index (FI), Physical Frailty Phenotype, and Identification of Seniors at Risk (ISAR) were used to explore the TaGA's validity. External scales were used to investigate the validity of each matched TaGA domain. The interrater reliability and time to complete the instrument were tested in a 53-person subsample. RESULTS: In 3 rounds of opinion, experts achieved consensus that the TaGA should include 10 domains (social support, recent hospital admissions, falls, number of medications, basic activities of daily living, cognitive performance, self-rated health, depressive symptoms, nutritional status, gait speed). They arrived at sufficient agreement on specific tools to assess each domain. A single numerical score from 0 to 1 expressed the cumulative deficits across the 10 domains. The TaGA score was highly correlated with the FI (Spearman coefficient = 0.79, 95% confidence interval (CI)=0.76-0.82) and discriminated between frail and nonfrail individuals better than the ISAR (area under the receiver operating characteristic curve 0.84 vs 0.72; P < .001). The TaGA score also had excellent interrater reliability (intraclass correlation coefficient = 0.92, 95% CI=0.87-0.95). Mean TaGA administration time was 9.5 ± 2.2 minutes. CONCLUSION: The study presents evidence supporting the TaGA's validity and reliability. This instrument may be a practical and efficient approach to screening geriatric syndromes in fast-paced healthcare settings. Future research should investigate its predictive value and effect on care.