The authors explore the use of portable hand-held spectral domain OCT (SD-OCT) in three eyes of three infants and young children with macular retinoblastoma. All were treated with chemotherapy and all had SD-OCT before and after treatment. The children were aged seven, nine and 33 months. In each case the tumour was exophytic with shallow subretinal fluid. No subretinal or vitreous seeding was noted. The foveaola was involved in one case. Mean tumour thickness by ultrasound was 4.8mm (four to six) and mean tumour base was 10.3mm (eight to twelve). Before treatment, the tumours showed smooth (two) or slightly irregular (one) surface topography and low to intermediate optical density by OCT. The normal anatomically intact retina appeared draped over the tumour in each case. After chemotherapy, tumour regression occurred in all cases. At one month, mean tumour thickness was 2.6mm (2.2-3) and tumour base was 6.8 (6-8). By OCT, tumour surface was smooth (one) and irregular (two). Subretinal fluid had almost resolved in all cases. At the tumour site, the retina showed full thickness disorganisation but with abrupt transition to normal retina in all cases. OCT was useful for anatomic monitoring of the macular area.