The Senate has rejected a bipartisan effort to expand federal background checks to more firearms buyers in a crucial showdown over gun control.
The proposal would have required background checks for all transactions at gun shows and online. Currently they must occur for sales handled by licensed gun dealers.
Wednesday's vote is seen by many as a blow to gun control advocates in the wake of December's massacre of children and staff at an elementary school in Newtown, Conn.
The roll call is also seen as a victory for the National Rifle Association which opposed the plan as an ineffective infringement on gun rights.
President Barack Obama made broadened background checks the centerpiece of his gun control proposals.