In　this　paper,　an　experimental　and　analytical　investigation　of　concrete-filled　steel　tubular　(CFST)　laced　columns　is　presented.　These　columns　consist　of　four　concrete-filled　steel　tubes　that　are　laced　together.　A　total　of　27　experimental　tests　were　conducted　to　quantify　the　column　failure　mechanism　at　ultimate　loads.　The　experiments　were　designed　to　obtain　the　load-deflection　curves.　These　curves　were　subsequently　used　to　quantify　the　structural　behavior　for　each　element　of　the　hybrid　column.　Experimental　results　indicate　that　the　compression　force　in　the　longitudinal　members　dominated　the　failure　mechanism　in　the　CFST　columns.　In-plane　bending　occurred　when　member　segments　reached　the　compression　failure　load.　The　forces　in　the　lacing　members　(diagonal　and　horizontal　bracing)　were　found　to　be　small　and　remained　in　the　elastic　range　through　failure.　The　experimental　study　was　used　to　validate　an　analytical　parametric　study.　The　analytical　study　showed　that　increasing　slenderness　ratios　and　eccentricities　reduced　the　ultimate　load　capacity.　Additionally,　finite-element　analyses　of　CFST　columns　based　on　four　in　situ　structures　were　performed　to　determine　the　ultimate　load-carrying　capacity　and　were　subsequently　compared　to　several　building　codes.　On　the　basis　of　the　analytical　results,　a　new　methodology　for　calculating　the　ultimate　load-carrying　capacity　is　proposed.　This　purposed　methodology　is　compared　with　five　different　building　codes　to　quantify　the　increased　accuracy.　©　2011　American　Society　of　Civil　Engineers.