BACKGROUND This study aims to evaluate the differences in oocyte stimulation, endometrial thickness, fertilisation rate and embryo quality at in-vitro fertilisation (IVF) in patients with documented growth hormone (GH) deficiency, after GH supplementation. METHODS This was a retrospective analysis of 20 cases of patients who were pregnant and had GH supplementation during IVF at the Singapore General Hospital between 1993 and 2003. All these patients had previously failed IVF due to poor stimulation, poor egg quality, poor fertilisation at intracytoplasmic sperm injection (ICSI) or failed implantation, and they had documented GH deficiency. These initial cycles were compared with their subsequent IVF cycles with GH supplementation. A non-parametric test was used for statistical analysis. RESULTS Embryo quality, determined by scoring the embryos on Day two using morphology, improved significantly after supplementation of GH (p-value is less than 0.001, median embryo score increased from 10.7 to 16). There was also a statistically significant increase in the fertilisation rate for those patients who had ICSI. There was no statistical difference in the number of oocytes retrieved or in the mean endometrial thickness with GH. CONCLUSIONS This study implies that GH supplementation may improve embryo quality in selected patients with GH deficiency. Its role in improving fertilisation rate at ICSI merits further research and evaluation.