Welfare and Institutions Code section 300, subdivision (a) is not unconstitutionally vague. Mother appealed from the jurisdictional and dispositional findings contending that Welfare and Institutions Code section 300, subdivision (a) is unconstitutionally vague because it fails to properly define what constitutes serious physical harm. The appellate court rejected the argument, finding that parents of common intelligence could discern what injuries fall within its reach. The phrase “serious physical harm” is no less specific than the phrase “great bodily injury” which has been upheld. Mother’s challenges to the sufficiency of evidence were also rejected.