Microfilming is an information system that utilizes micro images to record documents on film for preservation purpose. Microfilm is fine grain, high resolution film used to record micro-images. Microfilm is the only time tested media of preservation that can ensure permanence and durability of records intellectual value. Microfilm, if properly produced and preserved can survive over 100 years and tests are underway to prove 500 years life expectancy.

Preservation is the core function of the department as highlighted in CAP. 19 Section 4 (1a ) and microfilming has played a major role in ensuring records that are very old, fragile and bulky are reformatted by microfilming so that they can be accessed by present and future generation.The reason you microfilm your historical records is to permanently archive them in a durable, easily accessible format that is an exact representation of your document, as it was originally produced.

Even when the greatest care is taken, repeated handling of original archival material results in damage and eventually destruction. Copying the material on microfilm enables the archivist to remove the originals from active use so that they may be conserved, while still making the records available to researchers in microform format.

KNADS has been running microfilming programme since the later part of 1960s. About 12,000 microfilms (over 12 million documents) have been made since then. In late 1970's, KNADS started Migrated Archives Project for retrieving records that were taken overseas especially in the United Kingdom and other European countries before independence. Over 1,500 microfilms and 1,200 microfiche amounting to 2 million documents have been retrieved back to Kenya to date.