Abstract Introduction Intimacy is crucial for developing successful relationships as it strengthens bonds between partners. Intimacy has been ill-defined and inconsistently measured for decades; however, theorists and researchers consistently agree that intimacy features components of love, affection, self-disclosure, and mutual validation. These constructs feature both cognitive and behavioral aspects of human connection. Despite the importance of intimacy in relationships, there is no widely accepted measure that captures the full spectrum of this multidimensional construct. Popular measures like the Miller Social Intimacy Scale (MSIS), the Personal Assessment of Intimacy in Relationships (PAIR), and the Fear of Intimacy Scale (FIS) each address assess subjective feelings of intimacy. Though they may include behavioral items, the outcome of the scale is cognitive conceptualizations of feelings of intimacy. Extant scales do not sufficiently focus on the behavioral aspect of intimacy in relationships. The widely-accepted Interpersonal Process Model of Intimacy suggests that the exchange of intimate behaviors and experiences over time create these feelings of intimacy and its theorized components in a couple. As such, the development of a more inclusive, behavioral intimacy assessment would benefit both researchers and clinicians and help advance our understanding of this construct. Objective The current study aimed to identify specific acts or behaviors that elicited feelings of intimacy for individuals in order to develop a more nuanced, behavioral measure for use in future research and clinical practice. Methods In Study 1, 297 participants nominated over 2,700 items that “elicited feelings of intimacy” for them. Examples of nominations included: trust, communication, touch, attraction, and sex. Trained raters condensed duplicate items (e.g., kiss, kissing) and created a final list of unique nominations for use in Study 2. Five experts in the field of sex research submitted additional items for consideration in Study 2 based on previous conceptualizations of this construct. This process results in 45 distinct items; however, some of the items were behaviors like “sex, acts of service, and attention.” As such, the authors created items for self and partner initiated acts to reflect both the giving and receiving of intimate behaviors (e.g. giving and receiving acts of service). 105 items were compiled from Study 1 and Study 2. Results These 105 behavioral elicitors of intimacy comprise the Intimacy Checklist. In Study 2, 301 participants rated and confirmed that the items created in Study 1 were important to intimacy in varying degrees. Study 2 attempted but failed to identify a significant factor structure for the items. Conclusions The lack of a clear factor structure speaks to the complexity of this multidimensional construct; this is actually consistent with previous literature as there are numerous studies that suggest different factor structures of the same construct (i.e., 4 factor versus 8 factor models). The resulting Intimacy Checklist is a potentially powerful tool for identifying person-specific experiences of intimacy and preferences for intimate interactions in both clinical work and research. A follow up study will be conducted to determine if individuals who feel more satisfied with their intimate interactions are more sexually and relationally satisfied overall. Disclosure No