Self-tracking describes the measurement efforts of an individual towards collecting, storing, analyzing, as well as reflecting and acting upon data on personal activities. Technological innovations enhance the current trend for individuals to collect data of private activities such as walking, eating, expenditures, or resource consumption. Yet, despite predictions of such an emerging trend, many users show contradictory behavior (refuse to buy a device, stop using it). Thus, scholars increasingly attempt to explain this contradicting behavior. First approaches from adoption theory and cognitive dissonance theory encompass the concept of attitudes. I aim to enhance empirical research in this context by developing a specific attitude towards self-tracking scale that can be used in surveys with private individuals. In this research-in-progress-paper, we present domain specification and a first set of 65 items derived from 24 explorative interviews.