This paper addresses the question, how effective is the state’s mitigation effort in arresting the spread of Covid-19 in Illinois counties. To address this question, we use county data on number of Covid-19 cases; specifically, we compute the daily growth rate of infections as at April 11, 2020, estimate the likely number of cases as at April 23, 2020, and compare the estimate to the actual number of Covid-19 infections as at April 23, 2020. The differences in number of cases, from projected to actual number of Covid-19 infections, are used to rank the counties in terms of their effectiveness in mitigating the spread of the virus.