The objective of this study was to assess the bacterial etiology and effectivity of endotracheal aspirate (ETA) and mini-nonbronchoscopic, protected bronchoalveolar lavage (mini-BAL) cultures in early- and late-onset ventilator-associated pneumonia (EO-VAP and LO-VAP, respectively) in our intensive care unit. This prospective study was performed in all patients who were hospitalized in the intensive care unit beyond 48 hours and had possessed the VAP clinical criteria according to the Centers for Disease Control and Prevention. The bacterial etiology of VAP was investigated using ETA and mini-BAL samples collected within 24 hours after diagnosis of VAP. Ventilator-associated pneumonia cases that occurred within the first 5 days of intubation were described as EO-VAP; and the cases the occurred exceeding 5 days were described as LO-VAP. A total of 43 clinically diagnosed VAP episodes composed of 10 EO-VAP and 33 LO-VAP cases were studied in 31 patients. Endotracheal aspirate cultures yielded 11 isolates, and mini-BAL cultures yielded 9 isolates collected from samples of 10 attacks with suspected EO-VAP. Staphylococcus spp was the leading agent in EO-VAP cases as detected by both ETA (27.3%) and mini-BAL (33.3%) cultures. On the other hand, ETA cultures identified 22 isolates, and mini-BAL cultures identified 24 isolates in 33 attacks suspected with LO-VAP. Gram-negative bacteria were prominent in LO-VAP cases; Pseudomonas aeruginosa was the leading bacterium in both culture methods; ETA (42.4%) and mini-BAL (45.5%). Overall, ETA and mini-BAL cultures yielded similar results in patients suspected of having VAP. Morphologies of all 33 isolates (100%) obtained with ETA cultures and 30 (90.9%) of 33 isolates obtained with mini-BAL cultures were observed in Gram stain of relevant samples. According to our results, Gram stains of both ETA and mini-BAL samples can help the clinician to initiate the appropriate antimicrobial therapy and save time before obtaining the culture results.