Electronic Journal of Differential Equations, Vol. 2004(2004), No. 03, pp. 1-17. Title: Asymptotic properties, nonoscillation, and stability for scalar first order linear autonomous neutral delay differential equations Authors: Christos G. Philos (Univ. of Ioannina, Greece) Ioannis K. Purnaras (Univ. of Ioannina, Greece) Abstract: We study scalar first order linear autonomous neutral delay differential equations with distributed type delays. This article presents some new results on the asymptotic behavior, the nonoscillation and the stability. These results are obtained via a real root (with an appropriate property) of the characteristic equation. Applications to the special cases such as (non-neutral) delay differential equations are also presented. Submitted October 6, 2003. Published January 2, 2004. Math Subject Classifications: 34K11, 34K20, 34K25, 34K40. Key Words: Neutral differential equation; asymptotic behavior; nonoscillation; stability.