The following code shows how to enable word wrap in jqgrid header and body cells.

JQGrid cell word wrap

.ui-jqgrid tr.jqgrow td {
white-space: normal !important;
height:auto;
vertical-align:text-top;
padding-top:2px;
}

JQGrid Header word wrap

.ui-jqgrid .ui-jqgrid-htable th div {
height:auto;
overflow:hidden;
padding-right:4px;
padding-top:2px;
position:relative;
vertical-align:text-top;
white-space:normal !important;
}

Reposted from http://2centtech.blogspot.com/2009/12/jqgrid-header-and-cell-value-word-wrap.html