BACKGROUND: Acromegaly is a rare and progressive condition caused by excessive secretion of growth hormone and insulin-like growth factor type 1. Pasireotide long-acting release (LAR) is indicated as a second-line therapy for adults with acromegaly who are unsuitable for or unresponsive to surgery and inadequately controlled with first-generation somatostatin receptor ligands (FGSRLs). Although its efficacy and safety have already been established, its cost-effectiveness remains unclear. The primary objective of this study was to systematically assess the cost-effectiveness of pasireotide LAR compared to other second-line medical options, particularly pegvisomant. METHODS: A systematic literature review was conducted in May 2024 in Medline, Medline In Process, Web of Science, and the Centre for Reviews and Dissemination (CRD), York. Studies were eligible if they were full or partial economic analyses of pasireotide LAR as a second-line pharmacological treatment for adult patients with acromegaly. Studies not available in English and publications prior to 2009 were excluded. Included articles were assessed for transparency using the appropriate checklists. Data extraction focused on costs, incremental cost-effectiveness ratios and quality-adjusted life years. Formal data synthesis of outcomes was not undertaken due to the small number of studies and notable heterogeneity between them. Methodological assessment involving the evaluation of model inputs, data sources, and their alignment with the evidence on the course of disease and clinical practice was performed to examine the main factors contributing to discrepancies in cost-effectiveness outcomes and assess the credibility of the results. RESULTS: Of 160 records identified, six publications met the inclusion criteria. Their findings demonstrated variability. The critical assessment highlighted considerable variability in methodological rigor among the included studies. CONCLUSIONS: Evidence on pasireotide LAR's cost-effectiveness versus pegvisomant regimens remains inconclusive. Although two studies indicated that pegvisomant is more cost-effective, the study with the highest methodological credibility found that pasireotide LAR is a cost-effective alternative.