The objective of this study was to determine availability of medicines and diagnostic equipments in public and private health care facilities in Tanzania. Four regions participated in the study and for each region, two districts were randomly chosen, one rural and one urban, in which 67 health facilities were drawn studied. Sixteen medicines were picked from National Essential Medicines List and ten diagnostic equipments were selected and their availability determined. The Statistical Package for Social Sciences (SPSS) version 16.0 SPSS, Inc. Chicago, USA, was used to analyse data. Mean availability of medicines was 80% in studied facilities; regional mean availability of medicines was 86% for Dar es Salaam, 82% for Kilimanjaro, 85% for Mbeya, and 70% for Mwanza. Availability of diagnostic equipments in consultation rooms was 39% (N=143). Availability of medicines and diagnostic equipments in studied health facilities were sub-optimal and interventions to address the situation are required.