Consonant clusters in Bengali are very common word-initially and elsewhere due to a long history of borrowing from Sanskrit, a language with a large cluster inventory. A substantial number of non-initial clusters have also been borrowed from Persian. Some words borrowed from European languages also have the same features as those from the former two. A handful of words from non-standard dialects of Bengali include native clusters.

Native Bengali (তদ্ভব tôdbhôbo) words do not contain initial consonant clusters;^[1] the maximum syllabic structure is CVC (i.e. one vowel flanked by a consonant on each side). Many speakers of Bengali restrict their phonology to this pattern, even when using Sanskrit or English borrowings, such as গেরাম geram (CV.CVC) for গ্রাম gram (CCVC) "village" or ইস্কুল iskul (VC.CVC) for স্কুল skul (CCVC) "school".

Sanskrit (তৎসম tôtshômo) words borrowed into Bengali, however, possess a wide range of clusters, expanding the maximum syllable structure to CCCVC. Some of these clusters, such as the mr in মৃত্যু mrittu "death" or the sp in স্পষ্ট spôshṭo "clear", have become extremely common, and can be considered legal consonant clusters in Bengali.

English and other foreign (বিদেশী bideshi) borrowings add even more cluster types into the Bengali inventory, further increasing the syllable capacity to CCCVCCCC,^{[citation needed]} as commonly used loanwords such as ট্রেন ṭren "train" and গ্লাস glash "glass" are now even included in leading Bengali dictionaries.

Final consonant clusters are rare in Bengali.^[2] Most final consonant clusters were borrowed into Bengali from English, as in লিফ্‌ট lifṭ "lift, elevator" and ব্যাংক bêngk "bank". However, final clusters do exist in some native Bengali words, although rarely in standard pronunciation. One example of a final cluster in a standard Bengali word would be গঞ্জ gônj, which is found in names of hundreds of cities and towns across Bengal, including নবাবগঞ্জ Nôbabgônj and মানিকগঞ্জ Manikgônj. Some nonstandard varieties of Bengali make use of final clusters quite often. For example, in some Purbo (eastern) dialects, final consonant clusters consisting of a nasal and its corresponding oral stop are common, as in চান্দ chand "moon". The Standard Bengali equivalent of chand would be চাঁদ chãd, with a nasalized vowel instead of the final cluster.