Introduction: Niemann-Pick disease type C (NPC) is a lipid storage disease that can present in children or adults. The prevalence of NPC has been estimated at 1:1200.00 to 1:150.000. The classic presentation occurs in mid-to-late childhood with the insidious onset of ataxia, vertical supranuclear gaze palsy (VSGP), and dementia. Until now, there is no effective treatment.  The use of 2-hydroxypropyl-b-cyclodextrin has been shown good results. Methods: Report of two cases of NPC in girls, comparing PET-Scan, films, and NPC Clinical Severity Scale pre-treatment and after three years. Case description:  NBP, 10 years old, with NPC, has a deficit of motor coordination, discrepancy between executive and verbal potencial and behavioral symptoms with reduction in all areas. Show deficits in memory and attention and injury of abstraction. In use of Miglustat (Zaveska) and lamotrigine. MBP, 14 years old, with NPC, in use of Miglustat (Zaveska, 400 mg/day), shows an improvement of balance and intelligibility of speech, but with difficulty to memorize and assimilate new information. Presence of axial and appendicular cerebellar syndrome. Results: They started treatment with cyclodextrin by intravenous infusion twice a week and after one year, they had significantly lower scores for NPC Clinical Severity Scale and improved brain metabolism measured by PET-scan. Conclusion/discussion: The use of 2-hydroxypropyl-b-cyclodextrin in two NPC patients reduced NPC severity score and improve brain metabolism. This drug can improve the health of NPC patients.