  An equitable coloring of a graph $G=(V,E)$ is a (proper) vertex-coloring of
$G$, such that the sizes of any two color classes differ by at most one. In
this paper, we consider the equitable coloring problem in block graphs. Recall
that the latter are graphs in which each 2-connected component is a complete
graph. The problem remains hard in the class of block graphs. In this paper, we
present some graph theoretic results relating various parameters. Then we use
them in order to trace some algorithmic implications, mainly dealing with the
fixed-parameter tractability of the problem.
