These studies addressed 2 questions concerning interview-based hostility assessments: whether they are affected if the interview is conducted face-to-face versus telephone and whether they are stable across an extended time period. In Study 1A, 54 students were interviewed face-to-face and by telephone in a laboratory setting. Half the sample was reinterviewed in the laboratory 6 weeks later. The other half was reinterviewed by telephone at home. With 1 exception, all intraclass correlation coefficients (ICCs) comparing interview modes were above .62. In Study 1B, 48 adults were interviewed face-to-face in a laboratory and by telephone in their homes with a 2-week intervening interval. The ICC comparing interview modes was .78. In Study 2, 100 adults were interviewed face-to-face in a laboratory and approximately 4 years later by telephone in their homes. The ICC across interviews was .69. Thus, support was found for the stability of interview-based hostility assessments across interview methods and extended periods of time.