Gerontological interventions should address the various geriatric syndromes suffered by the elderly, such as neurodegenerative diseases. Therapeutic lying is an effective and humanizing strategy to deal with dementia, used by various disciplines in the social and healthcare fields. This intervention strategy is made up of all the different responses to reality that are given to a person with cognitive impairment. This study analyzes the validity of the Spanish adaptation of the Attitudes toward Lying to People with Dementia (ALPD) questionnaire, given to 253 social workers who directly and indirectly intervened with older people suffering from cognitive impairment in public and private centers in Spain during the year 2022. The results of the validity and reliability analyses support the psychometric quality of ALPD for use in Spanish social workers. The statistical results indicate a good fit of the bifactor model (person-focused and lie-focused) and show the questionnaire to be reliable, with adequate psychometric properties. The article concludes with a discussion of practical, formative, and ethical challenges for social work in the field of geriatric services.