Neurofibromatosis is divided in two distinct types neurofibromatosis I (Von Recklinghausen's disease, NF-1) and neurofibromatosis II (bilateral acoustic neurofibromatosis). It is transmitted as an autosomal dominant trait but 50% of new cases appear because of de novo mutations. The cardinal features of neurofibromatosis I (NF-1) are multiple neurofibromas, cafe au lait spots (CLS), axillary and inguinal freckling and pigmented iris hamartomas (Lisch nodules). In addition, the disease can be confounded by a broad spectrum of complications, such as various kinds of osseous lesions, stenosis of the renal arteries, optic glioma and learning disabilities. Malignant progression of tumors developing in NF-1 patients is a major cause of morbidity and mortality. Skin involvement in NF-1 is common. Patches of cutaneous pigmentation and multiple cutaneous tumors create the most conspicuous findings. NF-1 concerns the dermatologist because of its skin manifestations and the difficulties in their treatment. Objective The aim of this research was to evaluate the systemic control, which will allow us to make decisions on the treatment of someone who suffers from NF-1. In this way, we can have a primary control which will enable us to compare it with others in the future, if necessary. Material-Methods Thirty-three children and adults were studied in total who suffered from NF-1.They visited the Research and Treatment Centre of Genodermatoses of “Saint-Louis” Hospital, Paris, and the 2nd Paediatric clinic in Athens, “P. & A. Kyriakou”. The research lasted approximately 3 years (1996-1999). The definite diagnosis of NF-1 was based on the National Institute of Health (NIH) diagnostic criteria. The clinical examination together with the rest of the laboratories tests followed the Riccardi School. Results More than half of the patients had a family record of NF-1.The patient's age was between 5-18. All the patients had CLS on their skin, 2/3 of them had axillary and inguinal freckling and more than 2/3 developed cutaneous or subcutaneous neurofibromas. The clinical examinations and the laboratory tests revealed: (a) From the neurological examination pathological findings showed: 4 patients, the 50% percent of these patients suffered from headaches, whereas, their neurological examination was normal. Malfunctions of the urine bladder, learning disabilities, psychokinetic disorders, delay in walking, were noticed in one child. Another child with plexiform neurofibromas of the eye-socket had propto- sis of the upper eyelid, (b) The examination of the optic field was found pathological in 6 from 31 patients. All the patients had hamartomas in the celebral MRI. (c) Decrease in hearing was found 3 children and in scanning of the abdomen, neurogenic tumors revealed in 4 from 29 patients. Over than half of the patients had pathological findings in the X-ray of the spine. Conclusions Children with NF- 1 need clinical and laboratory examination even at preschool age in order to investigate the complications of the disease, to diagnose the neoplasies in the early stage and to take the appropriate medical and treatment decisions.