We describe a two-year-old girl with 22q13 deletion syndrome (MIM ♯ 606232), 46, XX, de l (22) (q13.31). ish del (22) (q13.31) (TUPLE 1+,ARSA–). The patient has hypotonia, normal growth, severe expressive language delay, mild mental retardation, and minor dysmorphic facial features. In addition, she had central diabetes insipidus that was diagnosed at age two days and resolved at age 27 months. To our knowledge, this association has not been reported previously. Infants with hypotonia, or those suspected to have this syndrome should have high-resolution chromosome analysis and fluorescent in situ hybridization (FISH) studies or molecular analysis, since the chromosomal deletion may be subtle and may go undetected on routine cytogenetic studies. The association of 22q13 deletion syndrome with central diabetes insipidus is reported for the first time.