Complex human service organizations encounter difficulties in achievin
g a desired level of coordination among their inter-related components
. The author examines the literature dealing with complexity and coord
ination, identifies relevant variables, and develops a rationale for a
set of hypotheses investigated in a set of child welfare agencies. Th
e findings confirm the negative relationship between complexity and co
ordination. This relationship was observed to be mediated by mechaniza
tion and communication. The author concludes that if the administrator
s of these agencies want to improve coordination and believe in creati
ng an environment for better communication, they should provide adequa
te mechanical facilities and enhance task-oriented internal communicat
ion.