SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K
CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(D) OF THE
SECURITIES EXCHANGE ACT OF 1934
Date of Report: March 8, 2006

NL INDUSTRIES, INC. RETIREMENT SAVINGS PLAN
5430 LBJ FREEWAY, SUITE 1700, DALLAS, TEXAS  75240
(Name and address of plan)

NL INDUSTRIES, INC.
5430 LBJ FREEWAY, SUITE 1700, DALLAS, TEXAS  75240
(Name and address of issuer of the securities held pursuant to the plan)

Commission file number - 1-640




ITEM 4.01. CHANGES IN THE PLAN'S CERTIFYING ACCOUNTANT.

(a) Previous independent registered public accounting firm.
(i) Effective March 8, 2006, the Pension and Employee Benefits  Committee of the
NL   Industries,   Inc.   Retirement   Savings  Plan  (the   "Plan")   dismissed
PricewaterhouseCoopers  LLP as the independent registered public accounting firm
of the Plan. The decision to change the independent registered public accounting
firm was approved by the Pension and Employee Benefits Committee of the Plan.

(ii) The reports of  PricewaterhouseCoopers  LLP on the financial  statements of
the Plan for each of the two years in the period ended December 31, 2004 did not
contain an adverse  opinion or  disclaimer  of opinion and were not qualified or
modified as to uncertainty, audit scope or accounting principle.

(iii)  During the years ended  December  31, 2004 and 2003 and through  March 8,
2006, there have been no disagreements  with  PricewaterhouseCoopers  LLP on any
matter of accounting principles or practices, financial statement disclosure, or
auditing  scope  or  procedure,  which  disagreements  if  not  resolved  to the
satisfaction  of  PricewaterhouseCoopers  LLP  would  have  caused  them to make
reference thereto in their reports on the financial statements for such years.

(iv) During the years  ended  December  31,  2004 and 2003 and through  March 8,
2006,  there have been no reportable  events (as defined in Regulation S-K, Item
304(a)(1)(v)).

(v) The Plan  provided  PricewaterhouseCoopers  LLP with a copy of this  Current
Report on Form 8-K and has requested that  PricewaterhouseCoopers LLP furnish it
with a letter  addressed  to the SEC  stating  whether or not it agrees with the
above statements. A copy of such letter, dated April 4, 2006, is filed herein as
Exhibit 16.1 to this Current Report on Form 8-K.

(b) New independent registered public accounting firm.

(i) The Plan  engaged  Sutton Frost Cary LLP as its new  independent  registered
public  accounting firm as of March 8, 2006. During the years ended December 31,
2004 and 2003 and through March 8, 2006,  the Plan has not consulted with Sutton
Frost Cary LLP regarding either (i) the application of accounting  principles to
a specified  transaction,  either  completed or  proposed;  or the type of audit
opinion that might be rendered on the Plan's financial statements, and neither a
written  report was provided to the Plan or oral advice was provided that Sutton
Frost Cary LLP  concluded  was an  important  factor  considered  by the Plan in
reaching a decision as to the accounting, auditing or financial reporting issue;
or (ii) any matter that was either the subject of disagreement,  as that term is
defined in Item 304(a)(1)(iv) of Regulation S-K and the related  instructions to
Item 304 of Regulation  S-K, or a reportable  event,  as that term is defined in
Item 304(a)(1)(v) of Regulation S-K.


ITEM 7.01. FINANCIAL STATEMENTS AND EXHIBITS.
(c ) Exhibits.
16.1 Letter  from  PricewaterhouseCoopers  LLP to the  Securities  and  Exchange
Commission.

SIGNATURES

Pursuant to the  requirements  of the  Securities  and Exchange Act of 1934,  as
amended,  the  Registrant has duly caused this report to be signed on its behalf
by the undersigned hereunto duly authorized.

NL INDUSTRIES, INC. RETIREMENT SAVINGS PLAN

By:               /s/ Gregory M. Swalwell
                  Chairman, Pension and Employee Benefits Committee

                                                      Date:  April 4, 2006