Introduction: The Clinical Pathology Laboratory of Dharmais Cancer Hospital serves as a referral laboratory for oncology and HIV testing. However, the existing manual registration process for referral examinations was inefficient and frequently resulted in errors in patient demographic data. This study aimed to develop, implement, and evaluate a web-based laboratory registration system integrated into the Dharmais Cancer Hospital Information System (SIRSKD) to improve referral laboratory services. Methods: This qualitative study employed an action research design. Twelve purposively selected informants, including hospital and primary healthcare IT staff, laboratory personnel, hospital marketing staff, and referring health center representatives, participated in focus group discussions (FGDs) conducted during the problem identification, pre-implementation, and evaluation phases. Data were audio-recorded, transcribed verbatim, and analyzed using thematic analysis. Results: Ten themes emerged from the analysis: human resources, leadership, organizational governance, digital transformation regulation, partial referral systems, hospital–laboratory networking, information quality, system quality, laboratory referral service improvement, and increased customer potential. The implementation demonstrated that users accepted the web-based registration system and perceived it as easy to use, with no major operational barriers during the implementation period. The system reduced dependence on manual registration, streamlined referral workflows, and was considered to have the potential to improve service efficiency and support future interoperability among healthcare facilities. Conclusion: The web-based laboratory referral registration system was feasible and well accepted by users, demonstrating its potential to improve the efficiency and quality of referral laboratory services. Nevertheless, broader implementation with a longer evaluation period and quantitative assessment is needed to determine its impact on service performance and laboratory outcomes.