Being a parent is complicated in typical circumstances, with a great psychological impact as well as feelings and experiences of great intensity. This impact is greater in families in vulnerable situations, such as those with children with mental health problems, receiving treatment in a clinical setting. Due to these challenges, parenting in these circumstances is often accompanied by experiences of stress. An approach that has shown evidence of effectiveness in mitigating the negative impact of stress is mindfulness-based interventions, including the Mindfulness-Based Stress Reduction intervention program. The Mindfulness-Based Stress Reduction intervention program is designed as a psychoeducational, instructional, multimodal, and structured program whose main objective is to provide strategies for the management, coping, and awareness of stress in order to reduce it. In this paper, a protocol for the implementation and evaluation of the original Mindfulness-Based Stress Reduction intervention program with the added positive parenting component is presented, in order to systematize the incorporation of a parenting component in the Mindfulness-Based Stress Reduction intervention program, analyze its effectiveness for parents whose children have mental health problems (in terms of stress, mindfulness, emotional intelligence, general health, and parental role), explore the mechanisms of change operating in this intervention as perceived by the participants, and examine the application of acquired strategies to daily life.