Improved concrete form systems (10) are provided which permit erection of the systems (10) in close quarters adjacent existing structures, e.g., the systems (10) may be successfully installed with as little as 2-½ inches of clearance between such existing structures. The systems (10) include spaced apart outer and inner wall sections (12, 14) each formed of juxtaposed, interconnected form panels (16, 18, 20, 22), with connection assemblies (24, 25) serving to interconnect the adjacent form panels (16, 18, 20, 22) of each wall section (12, 14), and to cross-connect the wall sections (12, 14). Each form panel has a planar panel segment (26) having side marginal connection structures (48) preferably including concave surfaces (50, 52). The connection assemblies (24, 25) have elongated connection elements (58, 82) having central openings (60a) and laterally extending legs (62, 64) which mate with the surfaces (50, 52) A series of elongated, threaded connector bodies (72) extend through the element openings (60a) and are threadably secured via threaded ferrules (70) forming a part of the elements (58), and nuts (84) forming a part of elements (82). The threaded connection of the bodies (72) serves to draw together the adjacent form panels (16, 18, 20, 22) by virtue of a camming action between the legs (62, 64) and the surfaces (50, 52). Such threaded connections also cross-connect the wall sections (12, 14).