Abstract: The invention relates to an attachment of the cutting deck assembly (3) with a main structure (2) of the lawn mower (1), to allow an easy disengagement of the cutting deck assembly (3) for cleaning and maintenance processes. A ride-on lawn mower (1) comprising a main structure (2) and a front mounted cutting deck assembly (3), wherein the main structure (2) comprises an elongated support member (4) for supporting the cutting deck assembly (3) in an operable position, characterized in that the cutting deck assembly (3) comprises an elongated attachment portion (8) adapted for sliding engagement with the support member (4) of the main structure (2) to form a rigidly secured mounting of the cutting deck assembly (3) to the main structure (2) and to enable a sliding dismounting of the cutting deck assembly (3) from the main structure (2).