lthough retinoblastomas represent only 3% of childhood neoplasias, in infants under one year of age they represent 14% of all malignancies. According to the “National Registry of Child Tumors (“Registro Nacional de Tumores Infantiles”, RNTI-SEHOP), between 24 and 27 cases of retinoblastom a are diagnosed annually in Spain. Retinoblastoma is the most frequent malignant tumour in childhood; 90% of cases are diagnosed before the age of five. The main aim of treatment is cure while preserving the organ and maintaining vision, with the lowest possible morbidity. However, on occasions, cure implies loss of vision. Leukocoria, a diagnostic but not pathognomic sign, may go unnoticed or not be correctly diagnosed. The differential diagnosis [1] is made between infectious processes, particularly toxocariasis (Toxocara canis), vascular processes, such as Coats’ disease, and cataracts. Hereditary forms usually appear before the age of one and sporadic forms around two years. Delay in diagnosis may imply the need for enucleation, central nervous system involvement or distal metastasis. A correlation exists between early diagnosis and success of treatment. Retinoblastoma is a peculiar tumour whose onset is due to suppression of a specific gene (RB1). RB1 was the first anti-oncogene described in a human neoplasia. While RB1 suppression is the first step in the chain of mutations that provoke onset of the tumour, in 80% of human neoplasias RB1 is suppressed at some point in the complex cascade of mutations that lead to the development of most human tumours [2, 3]. Retinoblastoma may present sporadically in the absence of a family history or in an autosomally dominant form with incomplete penetrance. Children without a family history usually present unilateral disease while in those with a family history involvement is predominantly bilateral. Enucleation is necessary in 30% of unilateral cases and survival currently exceeds 90%. Retinoblastoma may be one of the paradigms of multidisciplinary collaboration in the field of paediatric oncology. A child with retinoblastoma requires the support of expert specialists in the diagnosis, treatment and follow-up of the disease. Without an early diagnosis made by a paediatrician, the aims of cure and preservation of sight could not be achieved. The ophthalmologist should confirm the diagnostic suspicion (bearing in mind that retinoblastoma is the only case in which the clinical diagnosis is accepted without histological confirmation prior to treatment), define the stage based on different classifications (Reese-Ellsworth or the International) and contribute to the treatment plan: enucleation or preservation of the eye by local treatment consisting of cryotherapy, diode laser, laser photocoagulation or brachytherapy. The ophthalmologist must also follow the response to treatment by digital imaging for immediate comparison (RET CAM) and carry out long-term followup. The paediatric oncologist, together with the ophthalmologist and radiotherapist, decides the therapeutic management, which may entail chemoreduction [4] treatment and radiotherapy, either external beam radiation therapy or episcleral plaque brachytherapy. The role of the geneticist is to provide genetic counselling for the family circle. The radiologist also plays a part in the diagnostic process [5]. The pathologist must be able to determine exactly whether choroids, ciliary body, iris or anterior chamber are involved and whether the optic nerve is affected after enucleation, which would necessitate adjuvant chemotherapy. The psychologist has to supervise neurocognitive and sensory development depending on the treatment and its sequelae and collaborate with neurosensory rehabilitation teams. The paediatric oncologist, general paediatrician and adult oncologist should carry out a strict follow-up to detect early second malignant neoplasias, a notable increased risk in children with retinoblastoma, particularly hereditary forms [6]. The role of nursing staff in the care and support of the child and his family must not be forgotten. Five per cent of patients present extraocular disease and require more intensive treatment which generally includes high-dose che mo