This systematic review provides an overview of the impact of early writing in preschoolers and the effectiveness of handwriting interventions between kindergarten and second grade. Seven experimental studies (pre-K-7 yo) and eight handwriting intervention group studies (pre-K-2) were reviewed. The results suggest that writing letters in late preschool contributes to letter recognition. Elementary students benefit when handwriting is explicitly taught. Legibility improves with sufficient practice. Interventions underpinned by motor learning theory and cognitive learning strategies are effective in improving legibility; remediation of performance deficits are not supported. Implications for collaboration among teams and increased writing opportunities in pre-K are discussed.