This paper reviews response trends over 24 consecutive quarters of a National Random Digit Dial telephone survey. Trends for response rates and refusal rates are studied as well as the components of response rate, namely, contact, cooperation and completion rates. In addition other rates, including answering machine, busy and no answer are studied. While refusal rates declined over the six year period, contact and cooperation rates significantly declined causing response rates to decline. Answering machine rates and busy rates also showed a significant increase over time. Finally, correlation’s among the variables of interest are presented. The response rate is negatively correlated with the busy rate, the answering machine rate and the no answer rate. Implications of the above trends are discussed.