The aim of this article is to describe the development and initial validation of an instrument for comprehensively identifying the information needs state of individuals who performed the role of informal carers. This study used two phases: a qualitative phase for the generation and review of an item pool (data collected from nine informal carers) and a quantitative phase (data collected from 198 informal carers) for items reduction and evaluation through exploratory factor analysis, and assessed validity and reliability. The process revealed six measurement scales useful for operationalizing the information needs state of informal carers. A 23-item scale was derived consisting of recognition and nonrecognition of information needs and four states: recognized-demanded, recognized-undemanded, unrecognized-demanded, and unrecognized-undemanded information needs. The six constructs had satisfactory psychometric properties in terms of Cronbach’s alpha, which ranged from 0.60 to 0.775. This article provides evidence to support the convergent and discriminant validity of the information needs state scale. It enables researchers to comprehensively identify the information needs state of informal carers and potentially other groups.