This study was a first attempt to examine the potential use of the two algebra progress monitoring measures as indicators of student growth in algebra proficiency. Three research questions are addressed in this study. (1) Do the progress monitoring measures demonstrate reliability and validity? (2) To what extent do two different types of probes reflect changes in student performance over an 8-week period? (3) Is the rate of student growth on either of the measures related to other indicators of student proficiency/growth in algebra? Regarding the first research question, findings revealed that both types of probes possessed satisfactory levels of reliability and validity. To address the second research question, we calculated students' weekly growth using ordinary least square regression. We found that students grew .32 points each week on the Algebra Concepts probes, but had an average weekly decrease of .21 units on the Content Analysis-Multiple Choice probes. To address the third research question, we correlated the rate of student growth with teacher ratings of growth. We did not find a significant relationship between these two growth variables. The study also reports growth data for a small number of students with disabilities on the Algebra Concepts measure and a third measure, Basic skills