Sputum-culture confirmation guides tuberculosis (TB) diagnosis and patient management but has previously been reported to be low in the US-Affiliated Pacific Islands (USAPI). We evaluated factors associated with positive sputum-culture results by analyzing TB case surveillance and laboratory data, including sputa quality and quantity for diagnostic specimens from the USAPI. A lower proportion of sputum specimens were reported as culture positive from the USAPI (42%), compared with Hawaii (58%) and the United States (55%). Few (3%) sputa collected from TB patients in the USAPI had both optimal quality and quantity; 40% had optimal quality (mucoid), and 7% had optimal quantity (>5 mL). Suboptimal sputum specimen quality and quantity contributed to fewer sputum-culture positive results in the USAPI. Improving sputum collection and handling might lead to more culture positive results and ultimately improve patient care and TB control in USAPI.