Background: Adequate sun safety during childhood is crucial for decreasing skin cancer risk in later life. Although parents are an essential target group in applying sun protection measures for their children, insight into the determinants associated with their sun protection behaviors is limited. Aims: This study aims to identify the most relevant determinants in predicting multiple parental sun protection intentions and behaviors in different sun exposure situations. Method: A longitudinal survey study with two measurements was conducted among Dutch parents (N = 670) of children (4-12 years old). Twenty-seven sociocognitive determinants were examined in terms of relevance regarding four parental sun protection behaviors in different sun exposure situations. The Confidence Interval-Based Estimation of Relevance approach was used to visualize room for improvement (sample means) on all determinants and their association strengths (correlations) with sun protection intentions and behaviors. Results: Behavior-specific rather than generic determinants were most relevant in explaining all sun protection behaviors. Of these determinants, attitude, self-efficacy and action planning, and especially parental feelings of difficulty in performing sun protection behaviors, were most relevant. Altogether, the explained variance of all sociocognitive determinants was highest for shade-seeking behavior (R[superscript 2] = 0.41 and 0.43) and lowest for supportive behavior (R[superscript 2] = 0.19 and 0.29) in both planned and incidental sun exposure situations, respectively. Discussion: This study provides detailed insight into relevant sociocognitive determinants of parental sun protection behaviors in various sun exposure situations and directions for composing parental skin cancer prevention interventions. Conclusions: Future composition of sun safety interventions should emphasize on enhancing parental feelings of self-efficacy, especially for shade-seeking and clothing behaviors.