Producción Científica ; Background and objective. The aim of this study was to assess the changes induced in electroencephalographic (EEG) activity by a Snoezelen® intervention on individuals with brain-injury and control subjects. Methods: EEG activity was recorded preceding and following a Snoezelen® session in 18 people with cerebral palsy (CP), 18 subjects who have sustained traumatic brain-injury (TBI) and 18 controls. EEG data were analyzed by means of spectral and nonlinear measures: median frequency (MF), individual alpha frequency (IAF), sample entropy (SampEn) and Lempel-Ziv complexity (LZC). Results: Our results showed decreased values for MF, IAF, SampEn and LZC as a consequence of the therapy. The main changes between pre-stimulation and post-stimulation conditions were found in occipital and parietal brain areas. Additionally, these changes are more widespread in controls than in brain-injured subjects, which can be due to cognitive deficits in TBI and CP groups. Conclusions: Our findings support the notion that Snoezelen® therapy affects central nervous system, inducing a slowing of oscillatory activity, as well as a decrease of EEG complexity and irregularity. These alterations seem to be related with higher levels of relaxation of the participants. ; Ministerio de Economía y Competitividad (TEC2014-53196-R) ; Junta de Castilla y León (VA059U13 y BIO/VA08/15)