Two experiments were conducted to investigate the role of gestures on novel word learning in preschoolers. In Study 1, 20 children at the average age of 4;9 years were given novel words under 3 conditions: with support of iconic gestures; arbitrary gestures; no gestures, exemplifying a within-subject design. Results indicate scaffolding effects of both types of gestures in comparison to the control condition. No indication of gesture type effects could be observed even in children who were old enough to understand the iconicity of iconic gestures. Study 2 was implemented to further test the scaffolding effect of gestures vs. no gestures in children with SLI (n = 20) — but this time only iconic gestures were used. A between-subjects design was followed, using matched groups. Slow mapping was observed in addition to fast mapping within a 5-week-intervention period. Results confirm the scaffolding effect of iconic gestures on slow mapping in the clinical sample.