Abstract: An adjustable width bookend construction (10) including a pair of generally L-shaped bookend members (20)(20) each having a side wall (22) provided with a slot (24) and a rear wall (21) provided with a support member (23) wherein, the bookend members (20)(20) are operatively and slidably associated with one another via a cross-member (31) dimensioned to be slidably received within the slots (24)(24) and be slidably supported on the support members (23). Furthermore, the cross-member (31) is optionally provided with a pair of end cap members (32)(32) that prevent lateral displacement of the bookend construction (10) relative to and resting upon an elevated level surface. Furthermore, holding block assemblies (40) are optionally provided to prevent aftward displacement of the bookend construction (10) relative to a collection books.