This study aims to clarify the concept of saturation in qualitative research, which is crucial for improving nursing knowledge and ensuring evidence-based practice. The research employs an evolutionary concept analysis method, analyzing 33 articles and books published between 2005 and 2023. Saturation is defined as a context-dependent, subjective process that requires detailed systematic analysis. It is used in four ways: theoretical saturation, data saturation, code or thematic saturation, and meaning saturation. The antecedents of saturation are categorized into study-related factors (e.g., research objective, nature and sensitivity of the phenomenon) and researcher-related factors (e.g., researcher skill, knowledge, and biases). The consequences of saturation include ensuring credibility and quality in qualitative research and saving time, energy, and budget. The study concludes that understanding saturation and its types helps researchers optimize their studies by avoiding redundant data collection and ensuring valid results. Future research should explore how factors influencing saturation impact sample size estimation.This study aims to clarify the concept of saturation in qualitative research, which is crucial for improving nursing knowledge and ensuring evidence-based practice. The research employs an evolutionary concept analysis method, analyzing 33 articles and books published between 2005 and 2023. Saturation is defined as a context-dependent, subjective process that requires detailed systematic analysis. It is used in four ways: theoretical saturation, data saturation, code or thematic saturation, and meaning saturation. The antecedents of saturation are categorized into study-related factors (e.g., research objective, nature and sensitivity of the phenomenon) and researcher-related factors (e.g., researcher skill, knowledge, and biases). The consequences of saturation include ensuring credibility and quality in qualitative research and saving time, energy, and budget. The study concludes that understanding saturation and its types helps researchers optimize their studies by avoiding redundant data collection and ensuring valid results. Future research should explore how factors influencing saturation impact sample size estimation.