  In this note a new measure of irregularity of a simple undirected graph $G$
is introduced. It is named the total irregularity of a graph and is defined as
$\irr_t(G) = 1/2\sum_{u,v \in V(G)} |d_G(u)-d_G(v)|$, where $d_G(u)$ denotes
the degree of a vertex $u \in V(G)$. The graphs with maximal total irregularity
are determined. It is also shown that among all trees of same order the star
graph has the maximal total irregularity.
