Approximately 10-20% of head injury survivors sustain extensive neurological damage and remain minimally or inconsistently responsive to stimuli for 3-6 months postinjury. These patients, designated as slow to recover (STR), may be candidates for sensory stimulation programs rather than traditional rehabilitation. Medical and insurance personnel have resisted referral and payment for treatment because of the lack of objective measures of progress, a theoretical basis for treatment, and evidence of treatment efficacy. A valid, reliable assessment tool has recently been developed (Western Neuro Sensory Stimulation Profile) that assesses low-level cognitive/communicative function and documents improvement in STR patients. This article addresses the theoretical rationale for treatment. Evidence from four areas--sensory deprivation, enriched environments, nervous system plasticity, and sensitive periods of neurodevelopment--suggests that sensory stimulation programs are potentially beneficial for STR patients. Speech-language pathologists are encouraged to study the recovery patterns of STR patients and to determine the efficacy of treatment strategies.