Background: Proficient delivery of motivational interviewing (MI) is often determined by global rating of relational elements or cumulative tallies of technical elements. Yet limited empirical evidence exists to clarify how relational and technical elements are associated, or if rates of skill indices and their constituent technical elements vary within a clinical encounter. Aims: This study sought to document temporal variance in rates of MI skill indices and their constituent technical elements during brief clinical encounters with a standardized patient wherein delivery was “MI-proficient”, and to distinguish those temporal patterns from those observed in encounters with “MI-inconsistent” delivery. Method: Data were accessed from a large MI training trial wherein relational and technical elements of MI delivery were scored for 503 recordings of a simulated 20-minute clinical encounter. Notably, independent raters tallied technical elements in 5-minute segments, allowing evaluation of potential variance among the encounter's quartile intervals. Global ratings of MI spirit identified subsets of recordings with MI-proficient (n = 49) and MI-inconsistent (n = 43) delivery for stratified analyses. Results: Analyses contrast temporal trajectories of technical aspects of MI-proficient and MI-inconsistent delivery, with the former characterized by: 1) elicitation and reflective listening as primary opening strategies; 2) increased depth of reflective listening as a predominant strategy in subsequent, focused therapeutic discussion; and 3) increased use of elicitation and information provision in change planning as the encounter approached conclusion. Conclusions: Findings are generally consistent with seminal descriptions of MI (Miller and Rollnick, 1991, 2002), and document temporal aspects of skilful MI delivery in brief encounters.