Results link lower student-to-school-counselor ratios to better graduation rates and lower disciplinary incidents across Missouri high schools. An interaction favorable for promoting student success in school was found between increasing percentages of students receiving free or reduced-price lunch and smaller student-to-school-counselor ratios. In high-poverty schools, those schools that met the ASCA criteria of having at least one professional school counselor for every 250 students had better graduation and school attendance rates, and lower disciplinary incidents. (Contains 2 tables and 1 figure.)