Cancer diagnosis poses enormous physical and psychosocial challenges for both the affected person and their families. This systematic review identifies the characteristics and effectiveness of nursing interventions offered to adult patients with cancer and their families. Five databases were searched, and 19 studies published from 2009 to 2020 were included. Interventions were categorized as follows: (a) interventions with supporting and cognitive components (n = 3), (b) interventions that included skills training for the caregiver (n = 3), (c) interventions to enhance care through managing symptoms (n = 8), (d) interventions focusing on the dyad or family-patient relationship (n = 4), and (e) interventions targeted to the patient's condition (n = 1). The results of this review offer an overview from which to carry out new studies and are useful for providing future directions within family nursing practice, taking into account the impact that the family has on the disease and the consequences the condition may bring to the whole family.