<p>Performance measurement in newly created enterprises poses significant challenges due to conceptual ambiguities and methodological complexities. This paper offers a systematic conceptual review of how performance is defined, operationalized, and evaluated in early-stage ventures, drawing on strategic management and entrepreneurship literatures. Three interrelated contributions structure this review: (1) a critical synthesis of the conceptual tensions underlying performance definitions in startup contexts; (2) an integrative analysis of methodological challenges—including temporal instability, data accessibility, and multidimensionality—that complicate measurement; and (3) a proposed integrative evaluation framework combining survival thresholds, financial trajectory, strategic positioning, and entrepreneurial satisfaction. The paper explicitly acknowledges the social construction of performance and the legitimate diversity of stakeholder perspectives. By engaging with both foundational works and recent developments—including lean startup metrics, Balanced Scorecard adaptations, and OKR-based frameworks—this review contributes to a more nuanced understanding of evaluation practices suited to newly created ventures. Emerging 2025–2026 scholarship on startup incubator effectiveness (Seitz et al., 2026), performance management system development (Mancebo et al., 2025), and sustainable venture performance (Zangara et al., 2026; Almeida, 2026) is integrated to update the review. Practical implications are developed for researchers, support organizations, and policymakers. Limitations of the review approach, including its predominantly conceptual scope and the need for empirical validation of the proposed framework, are discussed.</p>