Sea buckthorn (SB) (genus Hippophae) is a berry-bearing, hardy bush of the family Elaeagnaceae that is widely spread in Asia, Europe and recently introduced to Americas. Feeding berries of SB has shown some health benefits that was associated with the abundance of various antioxidants (Pengzu et al., 2009). However, there is a lack of information on the impact of SB on the caecal short chain fatty acids (SCFA) fermentation and villus morphometry in broilers. Thus, the objective of the present study was to quantify the responses in caecal SCFA, jejunal villus height, crypt depth and the ratio between them resulting from feeding graded levels of SB from 7 to 21 d old broilers. The final body weight of birds was also measured. Feeding SB did not change the final body weight of the birds. Feeding graded levels of SB resulted in a linear decrease of the production of acetic, butanoic and pentanoic acids, which coincided with a linear increase in crypt depth and a decrease in the villus height to crypt depth ratio. There were no deviations from linear relationships for any studied variable. Reduction in villous height to crypt depth ratio, involving shorter villi and/or deeper crypts, and the reduced SCFA fermentation are usually associated with poor gut health. It appears that the serial substitution of a balanced diet with SB has a negative effect on SCFA production and gut morphometry, suggesting that higher oil content may cause the reduced caecal fermentation.