In the Kingdom of Saudi Arabia (KSA), hospital and population based statistics have shown that breast cancer has the highest crude frequency rate among Saudi women. The scarcity of reports about the disease in the KSA has been the impetus to this analysis about breast cancer in the eastern province of KSA. Data on female patients with invasive breast carcinoma seen at King Fahd Hospital of the University in the eastern province of KSA, were retrospectively reviewed. The analysis intended to examine the pattern of the disease and the outcome for patients. Between 1985 and 1995, 292 patients were identified. Their median age +/- SD (standard deviation) was 42 +/- 10.5 years. Most patients were younger than 50 years (78%) and were predominantly premenopausals (79%). Only 25 (9%) of patients had stage I cancer, whilst 130 (44%), 90 (30%), and 47 (16%) had stage II, III, and IV, respectively. Among patients with known axillary nodal status (242 patients), only 37% were node-negative whilst 32% and 31% had 1-3, and > or = 4 positive nodes, respectively. Adjuvant chemotherapy and tamoxifen were commonly offered; nonetheless, other adjuvant modalities were rarely utilised. The median follow-up +/- SD of all patients was 62.3 +/- 8.9 months: 152 patients (52%) were alive with no evidence of disease, 25 (9%) were alive with evidence of disease, and 115 (39%) were dead from breast cancer or its related complications. The median survival of the entire group was not obtained, but the 10-year projected survival was 55%. For stage I and II patients, 118 (76%) were alive with a projected 10-year actuarial survival of 64%. On the other hand, only 51 (57%) of patients with stage III disease were alive with a median survival of 41.5 months (95% Confidence interval (CI), 18.9 to 51.3). Patients with stage IV disease demonstrated a poor outcome with a median survival of 23.5 (95%, CI 12.2 to 31.4). Multivariate analyses were performed to explore the influence of independent variables on overall survival (OS) for patients with non-metastatic disease. Besides the expected adverse effect of disease progression, the favourable influence of adjuvant chemotherapy and tamoxifen prevailed. The amount of benefit gained from tamoxifen, however, was small. Similar analyses were undertaken to determine the influence of independent variables on progression-free survival (PFS). These analyses ascertained the adverse effects of advanced stage and the favourable impact of adjuvant chemotherapy. Breast cancer in the KSA has features that are distinctive from those of industrialised countries. Survival data, however, were comparable. The favourable influence of adjuvant chemotherapy was evident on both OS and PFS. Adjuvant tamoxifen, however, had little effect. Due to its infrequent use, the role of other adjuvant modalities could not be asserted.