Research investigating L2 (second language) willingness to communicate (WTC) has gained ground in the past two decades. Added to that is the emergence of complex dynamic systems theory (CDST) with a focus on the phenomenon of change, the implications of which for WTC research have opened up new avenues to enhance our conceptualization of the construct. Drawing on CDST, Segalowitz has proposed a framework that elaborates on the influences underlying speech fluency, including WTC. Drawing on this framework, the present exploratory study takes a qualitative and quantitative approach to examining the affective and cognitive dynamics of L2 learners' WTC, as well as how these interact with temporal measures of speech fluency, mainly focusing on speech rate, mean length of runs, and pause phenomena. Employing an idiodynamic method to capture moment-by-moment changes in participants' WTC, we monitored the interactions between cognition and affect manifested through WTC and speech fluency. The results demonstrate a non-continuous, mostly two-way, affective and cognitive interaction between WTC and L2 speech fluency.