Objective: Advanced statistical tools have created the opportunity to systematically examine the effect of early trajectories in predictors of therapeutic change, such as early alliance development patterns, on outcome. To date, however, these methods have been used almost exclusively to examine the effect of the development of early symptoms on later ones. Development patterns of alliance early in treatment, and their association with treatment outcome, have received much theoretical attention, but few systematic examinations have been conducted so far. Method: We integrated exploratory cluster analysis with the accumulated theoretical and empirical knowledge on patterns of alliance development to identify distinct patterns of early alliance development across the 1st 4 sessions of treatment in a sample of 166 patients receiving psychotherapy. Results: Three patterns of early alliance development were identified: early gradual strengthening, early repaired rupture, and early unrepaired rupture. The gradual strengthening and the repaired rupture patterns early in treatment predicted alliance strengthening later in treatment, whereas the unrepaired rupture pattern early in treatment predicted alliance stability later in treatment. The effect of early alliance development patterns on treatment outcome was moderated by pretreatment interpersonal problems: For patients with better interpersonal functioning at intake, the gradual strengthening and the repaired rupture patterns showed better outcomes, whereas for those with poorer interpersonal functioning at intake, the early unrepaired rupture pattern showed better outcomes. Conclusions: Findings suggest that early alliance development patterns affect treatment process and outcome.