The purpose of this research was to study stress and coping patterns of primary caregivers of adolescent psychiatric patients and its outcomes. 40 primary caregivers were purposive selected from primary caregivers of adolescent psychiatric patients who were hospitalized in Suan-prung Psychiatric Hospital, Chiang Mai Province. The data were collected through audiotape, and the interview protocol for demographic data, stress caregiving situations and coping patterns. Descriptive statistics were used to analyze the data. The content was classified into stress caregiving situations and coping patterns based on the stress and coping appraisal of Lazarus and Folkman. The results show that the primary caregivers experienced stress, when they encountered 6 stress caregiving situations. These included having inability to study or work, self-care deficit, problematic behaviors and symptoms, therapeutic problems of patient, financial problems, and the conflict between caregiver and other significant caregivers. Seven coping patterns that the caregiver have used to deal with 6 stress caregiving situations included: denial and negative response, relaxation oneself, escape/avoidance, resignation to ones fate, seeking social support, accepting and responsibility, and planful problem solving. In summary, the caregivers have a strong commitment in their role and their unconditional love, which has led to the acceptance and responsibility toward their mentally ill child. They attempted to deal with stressful caregiving situations by using multiple effective coping patterns. Most coping patterns help them resolve problems, and relieve stress except, denial and negative response, which led to negative outcomes for all of caregiving situations. The coping patterns which include relaxation oneself by drinking alcohol, and escape/avoidance of the situation of the patient noncompliance with treatment and medication, led to negative outcomes.