Helping family members engaged in the change process of therapy is an essential task of the therapist in the early part of the therapeutic process. Research demonstrates that fathers are frequently the least engaged family member in family therapy, but qualitative research into the nature of father engagement in family therapy is infrequent at best. This study aimed to understand factors that help or hinder fathers from becoming as fully engaged in therapy as mothers, in the fathers’ own words. The primary question that guided the development and execution of the study was, “What do fathers perceive as primary influences (i.e., barriers and facilitators) to their engagement in the therapeutic process?” A grounded-theory qualitative approach was used to assess what fathers with a child in family therapy believe makes therapeutic engagement easier or more difficult. The study used semi-structured interviews with 10 fathers whose child was the identified patient (IP) in family therapy to learn about their therapeutic experiences. These voices subsequently came together to demonstrate therapeutic influences in seven themes: the role of the therapist, the structure of therapy, fear of the unknown, the inherently difficult process of therapy, observation of therapeutic change, the child’s enthusiasm about therapy, and fathers’ role in therapy. Those themes led to a revised conceptual map that may lay the groundwork for a theory of therapist influence, helping therapists better identify the areas where they may have more influence and action about father engagement. Implications for further research and improved therapeutic engagement of fathers is discussed, including further studying the proposed conceptual map.