During the last two weeks of January 1944, the FSSF rested and recuperated at their Santa Maria barracks. New recruits were already being brought in and trained to fill the void from the losses sustained during their mountain campaigns. The first group was incorporated into Third Regiment to bring at least one regiment back up to full strength. There were enough Forcemen remaining in First Regiment to retain its organizational structure, but Second Regiment was so depleted that its six companies had to be merged into one battalion until more replacements could be trained and more of its members returned from hospital.

    On January 22, Allied forces made an amphibious landing at Anzio, just south of Rome and established a beachhead. The area was a flat plain crisscrossed by canals and drainage ditches. The eastern perimeter of the beachhead was defined by the Mussolini Canal. The FSSF was ordered to proceed by sea to Anzio and defend the first 13.4 km of the canal. They arrived on February 2 and spent the next 99 days in continuous engagement. They were supported by the 463th Field Artillery Battalion, 160th Field Artillery Battalion, and Company B-645th Tank Destroyer Battalion. Artillery played a major role at Anzio, and both sides conducted daily barrages against each other.

    The Force established machine gun nests and mortar stations along the canal as well as a line of forward observation outposts running parallel to it. Every day and every night, they sent out multiple patrols into German territory to gather intelligence, attack enemy installations, and capture prisoners for interrogation. Demolition patrols cratered roads and blew up farm buildings used by the Germans. Their constant aggression forced the enemy back and created a no man’s land east of the canal that was up to 1400 meters wide in some places. This landscape was covered in mine fields, and Force casualties from these hidden dangers were high.

    One of their early major successes occurred on February 9 when Second Regiment raided the German-held town of Borgo Podgora killing an estimated 74 enemy while only incurring 5 losses. Second Regiment conducted another major raid around Borgo Piave on February 19-20 in which 35 enemy were killed, but only 3 Forcemen lost. An impressive operation occurred on February 29 when a First Regiment patrol ambushed a German assault group near the canal, killing 12 and capturing 35. Over the next hour, more enemy units continued to walk into the ambush. In the end, a stunning 111 POWs were taken with only two minor Force casualties. Prior to the May 23 breakout from the beachhead, there were few engagements where the Force losses exceeded those of the enemy, but Force casualties were still high with 103 men killed, hundreds more wounded, and over a dozen men taken prisoners. The pressure from the constant dangers and the long period of front line deployment also caused over 90 cases of battle fatigue.