The effect of recombinant human growth hormone (rhGH) on sleep-disordered breathing (SDB) in Malaysian children with Prader-Willi syndrome (PWS) is under-investigated. We determined (a) the short- and long-term effects of rhGH and (b) factors associated with worsening SDB, in children with PWS on rhGH. This retrospective study included children with PWS (with and without rhGH) who had at least one polysomnography (PSG). Outcomes measured were the presence of SDB: before and after starting rhGH and the progress of SDB with and without rhGH. Serial insulin-like growth factor-1 (IGF-1) measurements were recorded. One-hundred and thirteen PSGs were analyzed. The majority (92.3%) of initial PSGs had SDB with AHI median (IQR) 5.0 (2.6,16.3) events/h. The age for receiving rhGH was median (IQR) 1.9 (0.7, 3.4) years old. A third (36.8%) had worsening SDB after initiating rhGH, which was associated with higher IGF-1 levels post-rhGH (p=0.007). After a median of 5 years of rhGH, 73.6% maintained or reduced their positive airway pressure (PAP) settings. Without rhGH, 80% had increased their PAP settings. Worsening SDB while on rhGH was associated with higher BMI, lower rhGH dose, higher IGF-1 levels and non-15q deletion. Majority of Malaysian children with PWS had SDB. At initiation rhGH, one-third of patients had worsening SDB, associated with increased IGF-1 levels. Stabilization of SDB was more frequently seen in those on long-term rhGH. Worsening SDB while on rhGH was associated with a higher BMI, on a lower dose of rhGH, higher IGF-1 levels and non-15q deletion.