The Legislative Branch of the Province of Buenos Aires is performed by two Bodies, one is the House of Representatives, and the other, the Senate.

The Senate is made up by forty-six senators, who must have proven the following requirements to be elected: any and every Senator shall be not younger than thirty years old, he/she shall be Argentine, either native or nationalized, having exercised his/her citizenship for five (5) years, and be living in this province for not less than one (1) year; and shall not hold office in any position for either for the nation or the province by virtue of his/her title or position be remunerated or compensated in any way whatsoever, in the Province or the Nation. Any and every Senator shall live in this Province by the time they render services to such position. They shall hold office for four (4) years, but the Body shall be renewed by one-second of the constituents every two years, therefore legislative elections will be held every two years. The Senate is ruled by a special Administrative Regulation, according to which employees and officers are appointed. The Vice-Governor shall be the President of the Senate, who, in case of a tie, shall only have the casting vote.

Meeting shall have a quorum when absolute majority of its members are present; nevertheless a smaller number may compel the absent member to attend the meetings in and under the terms and penalties said number may provide. Unless otherwise agreed by the majority, if not secret, sessions are open to public.

The Senate has a power which is exclusive to itself: the power to judge in public trial those impeached by the House of Representatives, serving thus, as judge and jury, and its members be on oath judge when sitting for such a purpose. If the Governor or the Vice-Governor is impeached, the Senate shall be presided over by the Chief Justice of the Supreme Court of the Province (Suprema Corte in Spanish), but the latter shall not have any vote. This judgement shall not extend further than to remove the accused individual from his/her office, and to disqualify him/her to hold any office position be remunerated or compensated in any way whatsoever, in the Province. No accused individual shall be stated guilty without a two-third of the casting votes of the members is present. The rest of the powers are shared with the House of Representatives, and shall be empowered: to lay taxes and levies provided that the provincial State so requires; to estimate resources and budgets to be spent; to create or eliminate jobs; to settle territory borders; to provide pardon, and agree amnesties for the offence of sedition in the Province; to provide any author or inventor, or those who improved or the first introducers of any new industry which be only performed within the Province, some privileges for a limited period; to enact laws which shall rule and enforce the liabilities stated for tax collectors and revenue officers of the Province and its municipalities, as well as to come into force those civic responsibilities of the state officers; to approve or reject any treaties drawn up by the Executive Branch with other Provinces; to grant honours and compensations for only one time, and with the consent of a two-third of the full number of the members of each Body, for services given to the Province; to enact the Fundamental Act of ‘Montepio Civil’; to organise the civil servant’s professional training; and finally, to enact all those laws necessary to apply the aforesaid powers in a better way as well as for all and any matters which are considered interesting for the citizens and the people in the Province, matters whose nature and subject are not restricted to those powers belonging to the Nation.