Background: Coronary artery disease (CAD) remains the number one cause of death worldwide. Chronic total occlusion (CTO) are defined as 100% occlusions with TIMI (Thrombolysis in Myocardial Infarction) 0 flow with at least a 3-month duration, observed in 15-30% of patients undergoing cardiac catheterization. Despite the high incidence of CAD, with the vast majority of patients carrying a high risk factor burden and co-morbidities, there is paucity of data regarding CTO in Saudi Arabia. , It is therefore of extreme importance to understand this challenging type of CAD. Aim: To explore the clinical characteristics and outcome of patients with CTO undergoing cardiac catheterization. Method: We collected data for all adult patients (age > 18 years) with a diagnosis of CTO who underwent coronary angiography at the Cardiac Catheterization Laboratory at King Abdul-Aziz Cardiac Center between January 2010 and December 2017 from electronic databases. We compared clinical characteristics and outcome of patients who underwent successful recanalization versus an unsuccessful outcome. The primary outcome was defined as mortality following the procedure. Secondary outcome was defined as MI, stroke or acute kidney injury as well as CABG required. Results are expressed as mean±SD or median, p<0.05 considered significant. Wilcoxon Rank Sums test for continuous and chi-square for categorical data. Results: In our cohort of 173 patients (mean age 60.2±11.4 years, female 17.9%), the most common risk factors were dyslipidemia (83.2%) and hypertension (76.3%). The most common co-morbidities were heart failure (32.9%) and CKD (12.7%). The most common admitting diagnoses included stable CAD (41.6%), NSTEMI (26%). LAD was the most common location (n=67), followed by RCA (n=63). The Wire was successfully crossed in 72.8 % of cases with < 50% stenosis post procedure observed in 50.3%. Female gender, older age, prior history of CABG and obesity were associated with a reduced likelihood of successful lesion crossing (p<0.001). Overall, mortality figures were; 30 day 1%; 6 month 2% and 1-year 4%, 10% of patients experienced MI ; 7% required CABG; AKI in 6% and stroke 1%. Patients with a successful crossing experienced a lower 30-day mortality (p<0.01) with no difference observed at 6-months and 1-yr mortality figures. Conclusion: To the best of our knowledge, this is the first CTO study in Saudi Arabia. Our results are generally in agreement with published data indicating that CTO is more prevalent in older men with a higher risk burden and located mostly in LAD. Our success rate for CTO PCI is comparable with current literature and shown to improve 30-day outcome in these patients.