The incident happened at around 11am on Monday in the Jacobs Island area of Blackrock.
A man is alleged to have approached an 11 year old girl at her home and asked her to go for a walk him.
The girl's mother intervened and took a picture of the man before reporting the incident to Gardaí.
Gardaí carried out a patrol of the area but no arrests were made.
Officers from Anglesea street are investigating the matter.
