The Mississippi Fan is composed of at least seven major depositional units (i.e., fanlobes). The sedimentary and seismic facies of the youngest fanlobe (late Wisconsin glacial stage) were studied to understand the sedimentation and growth patterns of this mud-rich, passive-margin submarine fan. This study incorporates seismic facies which were described in approximately 15,000 km of medium- and high resolution seismic reflection profiles and sedimentary facies which were described at nine DSDP core sites in the Mississippi Fan and in three industrial borings near the shelf margin. The seismic and sedimentary facies were calibrated at these locations. The inferred facies patterns reveal that fanlobe growth is mainly controlled by variations in volume and rate of sediment supply and relative sea level changes. Furthermore, these patterns are unique in the four physiographic regions. The (1) canyon region is an erosional conduit that grades into a leveed, depositional channel in the (2) upper fan region; the muddy deposits (slumps and turbidites) are typified by semitransparent and transparent seismic facies. The channel in the aggradational (3) middle-fan region is sinuous and migratory; the fill consists of basal coarse-grained deposits (high-amplitude reflections) capped by muds (semitransparent to transparent seismic facies). In the (4) lower fan region, parallel seismic facies indicate that the individual channel positions are ephermal and typically bifurcate prior to termination; this area consists of interbedded sands and muds mainly deposited as "sheets" from unchannelized turbidity currents. Extensive overbank deposits in all regions typically consist of fine-grained turbidites deposited by overbank spilling; they are characterized by reflection-free (updip) or parallel (downdip) seismic facies. Large-scale mass movement deposits (transparent seismic facies) on the middle fan were emplaced as slump/slide deposits in a non-channelized mode.