Abstract: An adjustable briefcase support device includes a body defining a receiving section and an upper frame connected thereto. The device further includes a plurality of elongated support members connected to the receiving section and are positioned rearward thereof. Such a plurality of support members extend substantially perpendicularly to the axis and have opposed end portions extending above the upper frame and below the body respectively. The plurality of support members are removably engageable with a vehicle seat for maintaining the receiving section at a substantially stable position during operating conditions. The upper frame includes female and male portions slidably engageable therewith and for selectively adjusting the top opening of the body so that various sized objects can be stored therein.