Birth registration in Ireland (including Northern Ireland) began in 1864.  The indexes,  you find on this site, are the 1st step of a 2 step process in finding a birth record registered in Ireland.  The Index will give you a full name, the registration district where the birth was registered and then the volume and page number where you can locate the record.

All of the 1864 Index is being transcribed and going online as a project led by the Ireland GenWeb Project.  If you would like to help, .

The following people helped transcribe the S's: 
Diane Culhane, Patricia McGill, Margaret Minoughan, Jan McMillan, Mary Devlin, Bob McConihe, Nora Fitzgerald, Jim Buckley, David Collins, Mary Mizzi, Rita Meistrel, Jim Cox and Pat Connors

NOTE:  The Index is being transcribed from the Family History Film #0101041.  While the film is in fairly good condition, there are pages that are very light so there may be some mistakes in transcription.  Some numbers are hard to define, especially  1 and 4.  Sometimes, you will find ? when we have had a problem deciding exactly what was typed.  Sometimes, a number is typed in error.  Therefore, you should refer back to the film, if you think you found a record you would like to see before ordering the record or checking out the record's film.
NOTE 2:  The Ss were extremely hard to transcribe due to the condition of the film.  First, the printing was very light and hard to read and some pages were blurry.  Therefore, you will find a bunch of ??.  It is recommended highly that if you think you found a name you would like to check the record on, first go to the Family History Library website and check the entry and then if you are sure of the volume, check all pages to find the entry you are interested in.

What are Registration Districts and where are they located?http://www.connorsgenealogy.com/RegDistricts.htm
This site gives much info on the districts, has a chart listing what counties they are located, plus all the Family History Library's film numbers for both the Indexes and the Records.

What do do next?
1.  If you find a record that you would like to see, go to:
http://www.connorsgenealogy.com/IrelandBirthRecordsLDS.htm
Under 1864, find the volume, and then get the film number

2.  You can find a record on the Family History Library site:
http://www.familysearch.org
Use the form on the left, enter full name, life event-birth, year-1864, year range-exact year, country-Ireland
Results will give parents' names, exact place of birth, source (FHL film where records are found)