<p>Action-state orientation (ASO) refers to regulatory modes influencing intention initiation and goal pursuit. While ASO pertains to both dispositional and time- and context-sensitive states, extant research predominantly focuses on individual differences in ASO, leaving within-person dynamics and situational antecedents underexplored. Addressing this gap, the study explored task-related fluctuations in ASO (ASO-T) and its relationship with task-related affect and anticipated task difficulty. Both the pilot study (<i>N</i>_person = 62, <i>N</i>_measurement = 248) and the main study (<i>N</i>_person = 165, <i>N</i>_measurement = 660) employed a biweekly data collection. However, in the main study, the assessment of anticipated task difficulty and other measures was temporally separated. Results of the pilot study indicated that the measurement of ASO-T is a reliable and valid instrument and ASO-T displays substantial within-person variation. The main study findings showed that task-related negative affect, but not positive affect, mediates the relationship between anticipated task difficulty and two forms of ASO-T (hesitation and preoccupation). Additionally, task-related positive affect was more strongly related to ASO-T than task-related negative affect. These findings confirm ASO-T as a context-sensitive and malleable construct and extend the ASO research by shedding light on task-related, situational antecedents of ASO-T.</p>