The purpose of this sequential exploratory mixed methods study was to develop and test a theory of planned behavior questionnaire that includes both direct and belief-based measures for seeking professional help from a MFT for participants and their spouses during times of relationship distress. To complete this goal, three focus groups (N = 24) were conducted to elicit the salient behavioral, normative, and control beliefs associated with seeking professional help from a MFT for participants and their spouses during times of relationship distress. The data was member checked and then analyzed using thematic analysis. Next, two quantitative measures were constructed, one using the salient beliefs elicited during the focus groups and the second using general questions that assessed participants' overall attitude, perceived norm, and perceived behavioral control. Both measures were placed online pilot tested (N = 102) using Qualtrics panels. The results suggest that the measures were accurate predictors of behavioral intention. The main stage then used both measures to assess the predictive ability of the elicited beliefs. The results also suggest that the beliefs accurately predicted participants' behavioral intentions for seeking professional help from a MFT for them and their spouses during times of relationship distress. The results also indicate that an intervention could be used to encourage troubled individuals, couples, and families to seek professional help from a MFT when experiencing relational issues. / Ph. D.