Health-related quality of life (QOL) outcomes are frequently used by clinicians, patients, and researchers for assessing the effectiveness of an intervention. Small differences in QOL may be statistically significant but their clinical relevance remains undefined. The smallest changes in QOL scores of the anterior skull base surgery questionnaire (ASBS-Q) which could be considered clinically significant have not been delineated. Here we present a meta analysis and review of the literature of 273 patients undergoing skull base tumor resection. The minimal clinically important difference (MCID), defined as "the smallest change in QOL which patients perceive as beneficial", was calculated using several statistical approaches. The MCID of the ASBS-Q was 0.4 (8%, score range 1-5). Various other instruments for QOL estimations revealed a larger range of MCID score (between 6.2%-17.5%) for the different QOL domains. The statistical analyses reveal that histology (benign vs malignant), time elapsed from surgery (< or ≥6 months), and surgical approach (open vs endoscopic) have significant clinical impact on different QOL domains. This paper brings level 1b evidence which demonstrates the importance of MCID as an adjunct for estimation of QOL in patients undergoing skull base surgery.