Introduction SBD is common in HK. The prevalence rate amongst middle-aged Chinese men and women was 9% and 3.7%. Polysomnography (PSG) is the gold standard diagnostic test while auto Continuous Positive Airway Pressure (ACPAP) therapy is the cornerstone treatment.  The demand?supply imbalance causes long waiting times for diagnostic tests in QEH. An ISSM was implemented for better service arrangement. Aims  to evaluate the outcomes of effectiveness. Methods Inter-hospital collaboration-ISSM was commenced on 1st October 2022 between Wong Tai Sin Hospital (WTSH) and Queen Elizabeth Hospital (QEH). The service model targeted to provide 700 In-Lab tests at WTSH, 380 home studies at QEH, and 200 nurse clinic sessions annually. It includes cross-hospital appointment booking, manual scoring, education provision, and compliance monitoring. The workflow including triage criteria, treatment priority, and category standardization between WTSH & QEH was formulated. Home studies including telemonitoring of ACPAP titration through the web cloud. Phone follow-up to tackle the problems if necessary. Result It was a 4-month review since October 2022 and 237 patients were triaged to WTSH whereas 294 were to QEH. The waiting time for urgent PSG and CPAP was improved by 70% (10 vs 3 weeks) and 50% (8 vs 4 weeks) at QEH. The waiting time for routine PSG was markedly reduced by 85% (165 vs. 24 weeks). The success rate of home studies was 98.6%.  Conclusion ISSM markedly shortens the waiting time for sleep tests and home studies play a significant role in waiting time reduction.