Objectives The current study examined whether various types of rumination are distinguishable and the effects of personal growth initiative (PGI) on posttraumatic growth, posttraumatic stress, and depression through adaptive and maladaptive rumination. Method Sample included 292 college students who experienced a potentially traumatic event (PTE). Results Intrusive and deliberative rumination were found to be distinct factors. However, brooding and reflection, thought to be separate aspects of depression, were a single factor. PGI was positively associated with growth and negatively associated with depression for both genders, and a negative relationship was found between PGI and posttraumatic stress among women. Indirect effects of PGI were found on posttraumatic stress and growth through different forms of rumination. These relations did not change after including the covariates (i.e., time since the trauma, direct exposure, and intentional harm). Conclusion The study provides new insight integrating rumination from the depression literature in the context of trauma and a potential benefit in applying PGI in alleviating pathology after a PTE and facilitating growth.